International Journal of Computer Engineering and Applications, Volume XII, Special Issue, March 18, ISSN

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1 SMART SOLUTION FOR LOW FREQUENCY PROBLEM IN SMART GRIDS Avani Pujara Abstract-Supply and load mismatch creates low frequency problems. Low frequency leads to unscheduled interchange which causes penalty to be paid by state utility to central utility. Different techniques have been proposed so far by various authors for controlling frequency under smart grid environment. This paper proposes low frequency problem solving based on sampling technique and RMS value algorithm for smart transmission system. Algorithm is developed for ABT (availability based tariff) meter and load prioritization is done for smart transmission system. Availability based tariff has three components in this methodology third component is discussed as it is frequency liked. Real time data is used to validate the proposed concept. Keywords: ABT, Unscheduled Interchange, Frequency linked component, Smart Grid, load prioritization, Sampling, RMS value, Real time, load mismatch, transmission system Dr. S.M. Bakre 1. INTRODUCTION Smart grid makes future power system abundant, clear, efficient and reliable. However, it may suffer from some challenges and problems. The effective frequency regulation is still a problem. Frequency instability leads to massive and cascade blackout in the power system. Restoration after blackout takes time. [1] Dr. V. Muralidhara v.muralidhara1952@gmail.com Proposed method provides smart solution based on Unscheduled interchange pricing and load prioritization using RMS value algorithm and sampling techniques. As a part of revolution in metering era Advanced metering infrastructure is implemented, ABT metering is part of advanced metering infrastructure is three-part tariff Third component of ABT is frequency based. Frequency control maintains the frequency of a power network at its nominal value when demand or supply fluctuates [2] frequency regulation can be achieved by two ways 1) by some regulatory approach like using under frequency relay or 2) by market based approach like frequency linked pricing. Load prioritization is nothing but shutting off by providing the feature of different range of frequencies in meter itself will control frequency back to range and mismatch of supply and demand can be overcome [3] Instead of getting schedule of dispatch of drawl next day and penalty charges details provided to state utilities the control circuit of ABT will control UI [4] Smart metering is the most important mechanism used in the SG for obtaining information from end users devices and appliances, while also controlling the behavior of the devices. Automatic metering infrastructure (AMI) systems. [5] AMI allows faster outage detection and restoration of service. It also provides customer with greater control over their electricity usage. AMI contains many devices like data management center master station communication center, intelligent terminal and smart meter. Among them smart meter is the key component of the advance metering Avani Pujara, Dr. S.M. Bakre, Dr. V. Muralidhara 1

2 SMART SOLUTION FOR LOW FREQUENCY PROBLEM IN SMART GRIDS infrastructure. [6] ABT is one of the component of AMI. following diagram shows ABT meter Sampling algorithm Fig. 1. Proposed ABT meter ABT meters and multifunction meters data is continuously monitored by ABT server located at central monitoring station from web server of LDC applicable charges for UI and mismatch between actual and scheduled is sent to state utility. [3] 1.1. RMS value algorithm Fig. 2 flow chart 1 Fig. 4 Total harmonic distortion flow chart 2 Fig 3 THD measurement [7] Total harmonic distortion value says how much distortion in fundamental values of voltage and current due to harmonics. Harmonic frequencies are component in a signal which are multiple of main signal. THD= VRMS without fundamental/vrms fundamental. Sampling rate and number of samples can give frequency, in meter three different range of frequencies are set to check load cut off as per priority. Proposed ABT meter itself is smart enough to shut down load if frequency goes beyond range 49.5Hz to 50.5 Hz for Avani Pujara, Dr. S.M. Bakre, Dr. V. Muralidhara 2

3 Indian power transmission system. There are at least two cases where the frequency determination from under sampled waveforms is useful. The first case is when only under sampled data is available. The second case is when it is desired to have as large detectable frequencies as possible given certain sampling rates. [7] Numerous studies have estimated the fundamental frequency of asynchronously sampled signals, and several interesting results have been published in recent decades [ 8]. Fig 4 shows the flow chart for frequency estimation procedure using total harmonic distortion value. Smart grid environment gives smart way of controlling frequency The smart grid is expected to revolutionize existing electrical grid by allowing two-way communications to improve efficiency, reliability, economics, and sustainability of the generation, transmission, and distribution of electrical power [9]. Unscheduled interchange charges are frequency dependent charges. It can be minimized by controlling frequency [10] Details: 66 KV Jiav substation Surat Total consumers on feeder :207 Total load :215 Amp Industrial load HP Commercial: MW Domestic load :4.27 MW Date :28/06/2017 Lowest frequency happened at 3:00 am Hz. As per proposed circuit of ABT meter the load must get shutoff as per priority. Domestic load is least priority load so it should get shutoff. In charge engineer of that jurisdiction will get message on smart phone from ABT meter itself and load will be shutoff automatically at the same time Frequency data for 24hrs: Tirupati feeder Table 1 Test feeder data. Sr No Time Frequency in HZ 1 1: : : : : : : : : : : : : : : : : : : : : : : : Fig 5 Frequency variation for test feeder Once 4.27 MW domestic load on feeder gets shut off frequency will come back to normal range and again at 4:00 am its 50 HZ. Load will be restored back CONCLUSION: Using of GSM technology and advanced metering infrastructure low frequency problem can be solved. proposed design of ABT meter where frequency range is provided in meter itself and load gets shut off as per priority is effective way of solving frequency regulation issues under smart grid environment. Table 1 shows frequency data collected for test feeder to understand 24 hours variation of frequency. Avani Pujara, Dr. S.M. Bakre, Dr. V. Muralidhara 3

4 SMART SOLUTION FOR LOW FREQUENCY PROBLEM IN SMART GRIDS 2. APPENDIX Source code-i // Algorithm -Sampling V & I Waves import java. util. Scanner; public class Main {public static void main (String [] args) {double I1, I3, I5. I7, I9 Scanner s=new Scanner(System.in); System.out.println("Read from port"); System, out. println ("Fundamental il ); i1=s.nextdouble(); System.out.println("Read i3, i5, i7 & i9"); i3=s.nextdouble() i5=s.nextdouble() i7=s. nextdouble ;i9=s.nextdouble() System.out.println('lih="+ih); ithd=ih/il System.out.println( l Ithd='l+ithd); double VI, V3, V5, V7, V9; System.out.println("Read voltages") ; v1=s.nextdouble() V3=s.nextDouble() v5=s.nextdouble() V7=s.nextDouble() v9=s.nextdouble() vh=math. sqrt((v3*v3)+(v5*v5)+( v7*v7)+( v9*v9)) System.out.println( vthd= +vthd):}} Source code II // Sampling of sinusoidal waveforms //Computation of various parameters import java.util. Random; publicclassmain( public static void main(string[] args) Random random=newrandomly: double a[j=new double[3000]: double b[]=new double[3000], double sum=0, sum1=0,sum2=0: for(int ( a[ij=random.nextdouble(): sum sum+la[i] a[i]), b[i]=random. nextdouble(): sum1=sum1+b[i] *b[i] sum2=sum2+( a[i] b[i]):) System.out.printIn("Sampling parameters ): double irms=(math.sqrt (sum))/3000: System.out.println(" lrms="+irms),double vrms=(math.sqrt/ sum1))/30 f System.out.printIn( Vrms= +vrms);double virms=vrms irms: System.out.printIn( VIrms= +virms); double p sum2/3000: System.out.printIn("Prms=" +p): System.out.println("pf="+p/virms):]) 3. ACKNOWLEDGMENT The Authors are grateful to Jain University, Bangalore for providing required research facilities and encouragement. The author gratefully acknowledges DGVCL Surat India for all the help with data of frequency. REFERENCES [1] Avani Pujara, Velhal Geeta Vilas, S.M. Bakre, V. Muralidhara Smart Way of Controlling Frequency Linked Component of Availability Based Tariff IEEMA journal volume 8 Issue no 8 April 2017 p. no ISSN [2] Enrique Mallada, Changhong Zhao, and Steven Low Optimal load-side control for frequency regulation in smart grids, arxiv: v3 [math. OC] 17 Nov 2015 [3] Velhal, G. Pujara, A.,Bakre, S.M. ; Muralidhara, V. Implementation of metering practices in Smart Grid,ICSTM-2015 IEEE Xplore. [4] Pujara, A., Velhal G Bakre, S.M. ; Muralidhara, V. Communication Feasibility Study for Smart Grid with Advanced metering Infrastructure IJEEER ISSN: x(E): X Vol.5, Issue6, Dec 2015 [5] Velhal, G. Pujara, A.,Bakre, S.M. ; Muralidhara, V.On progress of communication infrastructure for fault location and ABT metering,ieee 2015 [6] [7] Xiang-GenXia An Efficient Frequency- Determination Algorithm from Multiple Under Sampled Waveforms IEEE transactions on signal processing letters, vol. 7, no. 2, February 2000 [8] Joon-Hyuck Moon, Sang-Hee Kang, Dong-Hun Ryu, Jae-Lim Chang and Soon-Ryul Nam, A Two-Stage Algorithm to Estimate the Fundamental Frequency of Asynchronously Sampled Signals in Power Systems, energies ISSN [9] AtaulBari, JinJiang, WalidSaad,andArunitaJaekel Challenges in the Smart Grid Applications: An Overview Volume 2014, Article ID , InternationalJournalofDistributedSensorNetworks [10] K.V.V. Reddy, Ashwani Kumar, and Saurabh Chanana, Frequency linked pricing as an Instrument for frequency regulation market and ABT mechanism, /06/ 2006 IEEE. Avani Pujara, Dr. S.M. Bakre, Dr. V. Muralidhara 4

5 Avani Pujara has received her BE Electrical Engineering degree from Saurastra University. She earned her ME power system from Pune University. Her teaching experience is 9 years. She is currently a research scholar at. Her interest revolves around power system stability, smart grid and smart metering. She has published 3 papers in IEEE Xplore,1 paper in Elsevier journal, 5 papers in various international journals and 4 papers in National level conferences as a part of her research work. Dr. Shashikant M. Bakre completed his bachelor s degree in Electrical Engineering from Govt Engineering College Amravati (Nagpur University); followed by master s degree in engineering from COEP (Pune University). He also completed MMS, master s degree in management from Pune University. Later, he completed his doctorate from Bharati Vidyapeeth Deemed University, Pune in the year He is the author of ten books on computer engineering. Some of his books are Computer Fundamentals, Computer Master, Build your own website, OOPS and Core Java, Object Oriented Analysis and Design and Supply Chain Management. He has published about 25 research papers. Dr. V. Muralidhara Obtained B.E. in Electrical Engineering, M.E. in Power Systems from Mysore University and PhD from Kuvempu University. During the years 1975, 1978 and 2012 respectively. He has started his teaching career from PES College of Engineering Mandya during 1976 and served there for 6 years and retired as Prof. and Head of EEE at BIT, Bangalore and served there for 31 years. At present serving the School of Engineering and Technology, as an Associate Director. Published 4 papers in International conferences and one paper in International Journal as a part of the research work. His field of interest is Power Systems and High Voltage Engineering. Avani Pujara, Dr. S.M. Bakre, Dr. V. Muralidhara 5