iosr-JEEE   Volume-7 ~ Issue-4

Abstract: The study addresses the architecture of a hybrid PLL circuit technique for synchronizing a PV system with single phase grid. For determination of synchronization, the PV system is based on a reference system .The reference system is controlled by a microcontroller and pulse width modulation technique is used within the microcontroller to trigger the inverter in order to achieve efficient synchronization. Optocoupler is used to detect the real-time zero crossing detection and the digital phase lock loop system is used to control the phase angle and frequency of the system. The architecture of system is designed in Proteus simulator. The proposed architecture has performed well in reducing the harmonics produced because of inverter switching. Also if there are any abrupt changes in frequency or phase angle, the system can effectively manage changes.

Keywords: PV Array, Grid synchronization, Microcontroller, Optocoupler, DPLL, PWM and Power Quality.

[1] M.A.S Masoum, H. Dehbonei and E.F. Fuchs, "Theoretical and Experimental Analyses of Photovoltaic System with Voltage- and Current-Based Maximum Power-Paint Tracking,'' IEEE Trans. Energy Conversion, Vol.

[2] Z. Yishu, et al., "The circuit topology for single-phase Grid connected system and the control technology on converters, International Conference on Sustainable Power Generation and Supply, SUPERGEN '09, 2009, pp. 1-5.

[3] F. Blaabjerg, R. Teodorescu, M. Liserre, A. V. Timbus Overview of control and grid synchronization for distributed power generation systems, IEEE Trans. On Ind. Electronics, vol.53, pp. 1398-1409, Oct.2006. [4] P. W. Sauer, M. A. Pai, Power Systems Dynamics and Stability, Pren-tice-Hall, 1998.

[5] J.svensson, "synchronization methods for grid connected voltage source converters", IEE proceedings Generations, Transmission and Distribution, vol. 148, N0 3s, pp.229-235 May 2001.

[6] R. Weidenbrug, F.P. Dawson, and R. Bonert, "New synchronization method for Thyristor power converters connected to weak AC system" , IEEE Trans. On Industrial Electronics, vol. 40, N0 5, pp.505-511, Oct 1993.
[7] TMS320F/C240 DSP Controllers Reference Guide: Peripheral Library and Specgc Devices, Texas Instruments Incorporated.1999.17, No. 4, pp 514-522, Dec. 2002.

Abstract: With the advent of digital computers the engineers felt the need of utilizing computer advantages in the industrial process through the centralized control system. This thought led to the introduction of direct digital control (DDC) phylisophy. In this paper the author has presented a brief review of the structure of DDC as well as its working with illustration. The two types of algorithm used for programming as PID controller are discussed. The author has also pointed out the merits of DDC over analog control.Besides a few practical application has also been described.

Keywords: digital control, structure, algorithm,application

[1]. C.D JohnsJon, "Process Control Instrumentation Technology", 8th Edition, PHI, 11.
[2]. D. Patronobis "Principles of Industrial Instrumentation", 3rd Edition, TMH, 2010.
[3]. S.K Singh "Process Control Concepts, Dynamics and Applications", PHI, 
[4]. S. Bhanot "Process Control Principles and Applications", OUP, .
[5]. Krishna Kant "Computer Based Industrial Control", 2nd Edition, PHI, 12.
[6]. O.N Pandey, "Instrumentation and Process Control", Kataria & Sons, .

Abstract: Electric Power systems are composed of a very large number of subsystems and components which are subject to failures. The consequences of a failure of a component or subsystem may range from no effect at all on the operation of the system to wide-scale power interruptions caused by system instability. The cost associated with component failure may depend on the severity of the failure and on the corrective action undertaken to remedy the situation. In most of the cases, there will be some cost associated with the use of manpower and equipment. To solve this problem, a mathematical optimization technique was adopted to determine the optimum preventive maintenance periods and the number of men required to perform the Preventive maintenance such that the total maintenance cost is minimized. Results from the search technique, demonstrated a minimized maintenance cost rate.

Key Words: Preventive Maintenance, Inspection, Replacement, Availability, Breakdown

[1] Jardine, A. K. S., Maintenance, Replacement and Reliability, Pitman Publishing (reprinted editions available from Canadian Scholar Press, Inc. 211 Grenadier Road, Toronto, Ontario, Canada) 1973

[2] Sim, S. H., and Endrenyi, J, Optimal Preventive Maintenance with Repair, IEEE Trans., 1988 Vol. R-37, No. 1., Pp. 92-96.

[3] Anders, G. J., Human Failure Considerations in determining Optimal Inspection Interval for the Equipment Used in Emergency Conditions, IEEE Trans., 1985 Vol. SMC-15, No. 2, pp. 290-294.

[4] Apostolakis, G. E. and Bansal, P. P. Effect of Human Error on the Availability of Periodically Inspected Redundant Systems, IEEE Trans., 1977 , Vol. R-26, No. 3, pp. 220-225.

[5] Barlow, R. E., and Hunter, L. Optimum Preventive Maintenance Policies, Oper. Res., 1960, Vol. 8, pp. 90-100

[6] Gaertner, J. P. , Morgan, T. A., and Rodin, M. E. Insights Gained Through the Implementation of Reliability Centred Maintenance Practices at Nuclear Power Plants, in Proceedings of the 15th Inter-Ram Conference, Portland, Oregon, 1988, pp. 70-74

[7] Anders, G. J., Inspection Frequency and Availability of Emergency Equipment, Microelectron. Reliab., 1984 Vol. 24, No. 4, pp. 683 – 690.

[8] Keeney, R. L., Beley, J. R., Fleischauer, P., Kirkwood, C. W., and Sicherman, A. (1981), Decision Framework for Technology Choice. Vol. 1: A Case Study of One Utility's Coal-Nuclear Choice, Electric Research Power Institute Report No. EA-2153.

[9] Leitl, R., and Machek, J. On Optimum Preventive Maintenance Philosophy, Shoda Works, Nuclear Power Construction Division, Information Center, Report No. ZJE-274, 1986 Pilzen, Czechoslovakia.

[10] McWilliams, T. P. and Martz, H. F. Human Error Considerations in Determining the Optimum Test Interval for Periodically Inspected Standby Systems, IEEE Trans., 1980 Vol. R-29, No. 4 pp. 305-310

Abstract: In this paper we have designed a separately excited DC motor whose speed can be controlled using PID and fuzzy tuned PID controller first, the fuzzy logic controller is designed according to fuzzy rules so that the systems are fundamentally robust. There are 25 fuzzy rules for self-tuning of each parameter of PID controller. The FLC has two inputs. One is the motor speed error second is change in speed error and the output of the FLC i.e. the parameters of PID controller are used to control the speed of the separately excited DC Motor. The fuzzy self-tuning approach implemented on a conventional PID structure was able to improve the dynamic as well as the static response of the system. Comparison between the conventional output and the fuzzy self-tuning output was done on the basis of the simulation result obtained by MATLAB. The simulation results demonstrate that the designed self-tuned PID controller realize a good dynamic behavior of the DC motor, a perfect speed tracking with less rise and settling time, minimum overshoot, minimum steady state error and give better performance compared to conventional PID controller.

Keywords: DC motor: Fuzzy tuned PID: Speed control

[1] B.J. Chalmers, "Influence of saturation in brushless permanent magnet drives." IEE proc. B, Electr.Power Appl, vol.139, no.1, 1992. [2] C.T. Johnson and R.D. Lorenz, "Experimental identification of friction and its compensation in precise, position controlled mechanism." IEEE Trans. Ind ,Applicat, vol.28, no.6, 1992.

[3] J. Zhang, N. Wang and S. Wang, "A developed method of tuning PID controllers with fuzzy rules for integrating process," Proceedings of the American Control Conference, Boston, 2004, pp. 1109-1114.

[4] K.H. Ang, G. Chong and Y. Li, "PID control system analysis, design and technology," IEEE transaction on Control System Technology, Vol.13, No.4, 2005, pp. 559-576

[5] H.X.Li and S.K.Tso, "Quantitative design and analysis of Fuzzy Proportional-Integral-Derivative Control- a Step towards Auto tuning", International journal of system science, Vol.31, No.5, 2000, pp.545-553.

[6] Thana Pattaradej, Guanrong Chen and PitikhateSooraksa, "Design and Implementation of Fuzzy PID Control of a bicycle robot", Integrated computer-aided engineering, Vol.9, No.4, 2002.

[7] Weiming Tang, Guanrong Chen and Rongde Lu, "A Modified Fuzzy PI Controller for a Flexible-joint Robot Arm with Uncertainties", Fuzzy Set and System, 118 (2001) 109-119.

[8] PavolFedor, Daniela Perduková, "A Simple Fuzzy Controller Structure,"ActaElectrotechnica ET Informatica No. 4, Vol. 5, 2005

[9] Maher M.F. Algreer andYhyaR.M.Kuraz, "Design Fuzzy Self Tuning of PID Controller for Chopper-Fed DC Motor drive." Kuraz

[10] J.Klir. George, Yuan, Bo. "Furry Sets and Fuzzy Logic- Theory and Applications"

Abstract: Electrical Machine Design is a renown discipline of electrical engineering, which can be termed as the physical implementation of theoretical knowledge .A machine is designed considering different aspects like- quality and availability of materials, availability of suitable mechanism and skilled labor, cost, durability etc. In this paper, a computer based model (using SIMULINK) is furnished for obtaining the suitable dimensions of a three phase squirrel cage induction motor. The main objective of the work is to determine the dimensions of various parts and components of the motor, specify suitable materials for design and obtain the output parameters. Now-a-days, induction motors have become the workhorse of the industrial sector due to their easy means of construction and maintenance. Therefore, the performance of the machine needs to be specified using computer aided programs. In this paper, the input parameters of the induction motor is so chosen that it will offer a very competitive pricing and good efficiency.

Keywords: Electrical Machine Design, End ring, Squirrel cage Motor, SIMULINK

[1] I.J. Nagrath, D.P. Kothari, Electrical Machines (New Delhi, Tata McGraw-Hill Publishing company Limited, 2003)
[2] The MathWorks, Inc , Simulink- Dynamic System Simulation for Matlab (Natick, M A, USA, The MathWorks, Inc, 2000)
[3] A.K. Sawhney, A Course in Electrical Machine Design (Delhi, Dhanpat Rai & Co,2003)
[4] K.M. Vishnu Murthy, Computer-Aided Design of Electrical machines (Hyderabad, B.S. Publications, 2008)
[5] A.K. Tyagi, MATLAB and Simulink for Engineers (New Delhi, Oxford University Press, 2012)

Abstract: A soft-switching dc/dc converter with high voltage gain is proposed in this paper. The proposed converter reduces switching loss of active power switches and raises the conversion efficiency by using zero voltage switching (zvs) and zero current switching (zcs) techniques. This paper provides the effective solution for reverse recovery problem of the output rectifier by controlling the rate of change of current through diodes with the help of leakage inductance of a couple inductor cell. The proposed converter also provides continuous input current and high voltage gain. Experimental results obtained on 200W prototype are discussed..

Index Terms: Boost converter, high voltage gain, soft switching.

[1] F. Blaabjerg, Z. Chen, and S. B. Kjaer, "Power electronics as efficient interface in dispersed power generation systems," IEEE Trans. Power Electron., vol. 19, no. 5, pp. 1184–1194, Sep. 2004.

[2] R. J. Wai, W. H. Wang, and C. Y. Lin, "High-performance stand-alone photovoltaic generation system," IEEE Trans. Ind. Electron., vol. 55, no. 1, pp. 240–250, Jan. 2008.

[3] C. Wang and M. H. Nehrir, "Power management of a standalone wind/photovoltaic/fuel cell energy system," IEEE Trans. Energy Convers., vol. 23, no. 3, pp. 957–967, Sep. 2008.

[4] R. J. Wai and W. H. Wang, "Grid-connected photovoltaic generation system," IEEETrans. CircuitsSyst. I, Reg. Papers, vol. 55, no. 3, pp. 953–964, Apr. 2008. [

5] R. J.Wai, C. Y. Lin, R. Y. Duan, and Y. R. Chang, "High-efficiency power conversion system for kilowatt-level distributed generation unit with low input voltage," IEEE Trans. Ind. Electron., vol. 55, no. 10, pp. 3702–3714, Oct. 2008.

[6] K. Kobayashi, H. Matsuo, and Y. Sekine, "Novel solar-cell power supply system using a multiple-input DC–DC converter," IEEE Trans. Ind. Electron., vol. 53, no. 1, pp. 281–286, Feb. 2006.

[7] S. K. Mazumder, R. K. Burra, and K. Acharya, "A ripple-mitigating and energy-efficient fuel cell power-conditioning system," IEEE Trans. Power Electron., vol. 22, no. 4, pp. 1437–1452, Jul. 2007.

[8] C. Wang, Y. Kang, B. Lu, J. Sun, M. Xu, W. Dong, F. C. Lee, and W. C. Tipton, "A high power-density, high efficiency front-end converter for capacitor charging application," in Proc. IEEE APEC, Mar. 2005, vol. 2,pp. 1258–1264.

[9] Z. Qun and F. C. Lee, "High-efficiency, high step-up DC–DC converters," IEEE Trans. Power Electron., vol. 18, no. 1, pp. 65–73, Jan. 2003.

[10] X. Kong and A. M. Khambadkone, "Analysis and implementation of a high efficiency, interleaved current-fed full bridge converter for fuel cell system," IEEE Trans. Power Electron., vol. 22, no. 2, pp. 543–550, Mar. 2007.

Abstract: Low voltage insulators form an essential part of the electric power transmission system. Any failure in the satisfactory performance of low voltage insulators will result in considerable loss of capital, as there are numerous industries that depend upon the availability of an uninterrupted power supply. In this work, an 11KV porcelain insulator contaminated by different pollutants such as Salt, Cement, Ash, Acid rain and carbon II oxide was tested using a PGK 250KV transformer to ascertain the breakdown voltage of the insulator due to the different pollutants.Test results were recorded as follows: Dry insulator 90KV, dry insulator with water 78.3KV, dry insulator with cement 90KV, wet insulator with cement 20KV, dry insulator with ash 70KV, wet insulator with ash 25KV, dry insulator with Salt 70KV, wet insulator with Salt 20KV and dry insulator with carbon II oxide 78.3KV.

Keywords: pollutant, low voltage, insulator, environment, dielectric

[1] www.sustainability.vic.gov.au/resources/.../Insulation_benefits.pdf [2] http://en.wikipedia.org/wiki/Electrical_conductor

[3] http://en.wikipedia.org/wiki/Insulator

[4] http://www.ehow.com/list_7176657_types-insulators-transmission- lines.html

[4] http://www.ehow.com/list_7176657_types-insulators-transmission- lines.html

[5] Gencoglu M.T., Cebeci M., "Investigation of Pollution Flash Over on High Voltage Insulators using Artificial Neural Network", "Expert Systems with Applications" Vol.36, Issue 4. Pp. 7338-7345. (2009).

[6] Ramos Hernanz, José A.1, Campayo Martín, José J and et al "Insulator pollution in transmission lines" available at www.icrepq.com/icrepq06/256-hernanz.pdf.

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[8] Disendorf. W, "Insulation Co-ordination in High Voltage Electric Power System‟, London, Butterworth and Co Publisher, 1974

[9] Early B.P "The Transmission and Distribution of Electric Energy‟, London the English Press Ltd, 1958

[10] GonenTuran" Electric Power Transmission System Engineering: Analysis and Design‟, New York, John Wiley & Sons, 1988

Abstract: The dynamic behaviour of two tank interacting system was studied by the introduction of a step change in the manipulated variable (flow rate) and measuring the controlled variable by development of the suitable mathematical model of the system. This paper describes how the effect of the interaction of this interacting system is minimized by the design of the suitable de-coupler for the system and also includes the analysis of the interacting loops between the controlled variable that is liquid level of both tank and manipulated variable that is inlet flow rate. Generally in two tank interacting system there is no inlet flow rate for tank two , but this paper simplifies the industrial interaction problem where different tanks has different inlet and this is done by the help of relative gain array method. The result exemplifies that the gain of each loop is reduced approximately half when the opposite loop is closed and the gain of other loop changes the sign when the opposite loop is closed. Thus the decoupling is the most appropriate method for achieving minimal interaction and is most efficient method.

Keywords: Controlled variable, De-coupler, Interacting loops, Interacting tanks, Manipulated variables.

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Abstract: This paper presents identification and control of a DC motor. The dynamic model of the DC motor was first developed through system identification using least square parametric estimation method. Based on the developed dynamic model a state feedback tracking controller was then designed using optimal linear quadratic regulator for speed and position control of the DC motor. The developed dynamic model of the DC motor was validated via simulations and experiments. The performance of the controller was also verified through experiment.

Keywords: DC Motor, Linear Quadratic Reqgulator (LQR), Parametric Estimation Method (PEM)

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Abstract: BLDC (Brushless DC) motors have found a wide range of applications in industrial automation, automotive, aerospace, instrumentation because of their long operating life, compact form, reliability and low maintenance, high efficiency and better speed torque characteristics. This Paper is an endeavor towards developing a simulink model with the parameters of a real trapezoidal back-emf type of BLDC motor. The model is then analyzed under aiding and opposing loads.. The variations in motor speed-torque characteristics, back emf and current drawn by the motor for both no-load and loaded (aiding and opposing loads) conditions is analyzed. Some experimental tests are conducted to analyze the model and compared with the simulation results which are very useful in studying the performance of motor system.

Key words: Brushless direct current (BLDC) motor, trapezoidal back-emf, SIMULINK / MATLAB.

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[5]. "Simulation of Four Quadrant Operation & Speed Control of BLDC Motor on MATLAB / SIMULINK", IEEE Region 10 Conference, Nov 2008.

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