Rastko Zivanovic (PhD University of Cape Town)

Senior Lecturer / The University of Adelaide

 

Professional Interests

 

Control of Electric Power Systems, Power System Modelling and Simulation, Protective Relaying and Measurements in Power Systems

 

Applications of: Digital Signal Processing, Control Systems, Dynamical Systems, Intelligent Systems and Soft Computing, Scientific Computing, and Modern Statistics

 

Current postgraduate students

 

1. Hoong Ooi, PhD topic: Sensitivity Analysis of Transmission Line Fault Location

A fault location result is influenced by a series of modelling equations, signal processing hardware & software, setting parameters and system factors reflected in voltage and current inputs. All these factors are subject to many sources of uncertainty including measurement and signal processing errors, setting errors, as well as absence of information and incomplete modelling of a system under fault condition. This imposes a limit on our confidence in the fault location result. A complete practical fault location tool has to provide an estimate of the confidence in the result, possibly assessing the uncertainties associated with the influencing factors. In this research we apply a novel global sensitivity analysis technique to determine factors that mostly contribute to the fault locator output variability. Interactions between factors can be also determined, as well as regions in the space of input factors for which the result variation is maximum. In practice, such analysis can help in selecting the optimal fault locator for a specific application and also can help in the calibration process.

 

2. Mustarum Musaruddin, PhD topic: Automated Fault Analysis in Power Systems via Application Service Provider

The analysis of faults and disturbances was in the past, and will also be in the future, a fundamental foundation for a secure and reliable electrical power supply. The introduction of the digital recording technology opened new dimension in quantity and quality to the fault and disturbance data acquisition. Today the challenge is to automatically convert data to knowledge, which frees the manpower to implement corrective or preventive action. The automated analysis system proposed to be developed in the scope of this PhD project would perform the mathematical analysis of all (presently known) patterns of incorrect behaviour (disturbances and faults) automatically and only short message would be issued for the controllers (operating personnel) summarizing the required information and knowledge regarding the faults and the corrective measures. The automated analysis system will be available for use via the application service provider technology over the Internet as part of the project.

 

3. Hui-Min Tan, PhD topic: Transient Stability Sensitivity Analysis

Transient stability assessment and control is more difficult in current deregulated environment than before. This is due to the frequently changing generation/load patterns and network topology during normal power system operations. Competitive market, load increase and limited transmission capacity keeps the power system closer to the security margin. Disturbances may put the system into an emergency state, resulting in cascading outages and possible system collapse if there are no fast and appropriate stability controls in action. This research work will investigate some improvements of the conventional off-line time-domain transient stability tools used to define stability control schemes for real-time operation. In the first phase the research will focus on power system modelling for transient stability studies. The selected models will be used to formulate the complete model of a power system in the form of combined non-linear differential and algebraic equations. Time-domain solution techniques will be applied to solve such model for different operational conditions and different values of selected parameters. In the second stage a sensitivity analysis technique will be applied to study influence of various parameters and operational conditions on the transient stability margin. In the final stage we will demonstrate the application of the sensitivity analysis to determine the optimal transient stability controls.

 

4. Chen Shuo, MSc topic: Broken Bar Detection using High-Resolution Spectral Analysis

Spectral analysis of the signals (current or flux) recorded during operation of an induction motor can be used for detection of broken bar fault as well as estimation of the number of broken bars in the rotor. In the conventional approach based on the Fast Fourier Transform (FFT) spectral analysis very long data window with stationary motor load is required to separate fundamental frequency (50Hz) from the fault (broken bar) frequencies. When load decreases the fault and fundamental frequencies are coming closer and the data window for FFT approach should be enlarged. The goal of this research is to make accurate broken bar detection and estimation using short data window even for the case of lightly loaded induction motor. It is envisaged that the high-resolution parametric spectral estimation techniques can replace FFT and provide improved accuracy for short data windows. Such technique will have high value in the practical cases when machine load is slowly-changing in time.

 

Postgraduate students completed (last five years)

 

1. Abhisek Ukil, completed 2005, PhD title: Abrupt Change Detection in Automatic Disturbance

Recognition in Electrical Power Systems

2. Jaco Jordaan, completed 2006, PhD title: Fast and Accurate Signal Processing Algorithms for

Power System Applications

3. Peter Robert Van Heerden, completed 2006, MSc title: Produce a Simulation Model of the

Alpha / Beta 765KV Line to Evaluate Methods of Auto-Reclosing

4. Rhulani Matshidza, completed 2006, MSc title: Distance Protection Performance Concerning High Resistance Faults

5. C.H. van Staden, completed 2004, MSc title: Metal Oxide Varistor Overvoltage Protection for

Series Capacitors

6. P.Spasojevic, completed 2004, MSc title: A Practical Approach to Fault Analysis in Electrical

 Power Transmission Networks

7. W.Graupe, completed 2002, MSc title: A Short-Term Electrical Load Forecasting Model based

on Local Polynomial Modelling

 

Publications (last five years)

Book Chapters

1.      R.Zivanovic, “High Voltage Measurements”, Chapter 4, topic Electrical Engineering, editor Kit Po Wong, of the Encyclopaedia of Life Support Systems (Physical Sciences, Engineering and Technology Resources), www.eolss.net, EOLSS Publisher Co. Ltd. Oxford, UK, 2003

Journal Papers

1.      R.Zivanovic, “An Adaptive Differentiation Filter for Tracking Instantaneous Frequency in Power Systems”, IEEE Transactions on Power Delivery, Vol.22, No.2, April 2007

2.      A.Ukil, R.Zivanovic, “Application of Abrupt Change Detection in Power Systems Disturbance Analysis and Relay Performance Monitoring”, IEEE Transactions on Power Delivery, Vol. 22, No.1, January 2007, pp. 59-66

3.      A.Ukil, R.Zivanovic, “The Detection of Abrupt Changes using Recursive Identification for Power System Fault Analysis”, Electric Power Systems Research, Volume 77, March 2007, pp.259-265

4.      A.Ukil, R.Zivanovic, “Abrupt Change Detection in Power System Fault Analysis using Adaptive Whitening Filter and Wavelet Transform”, Electric Power Systems Research, Volume 76, June 2006, pp. 815-823, in TOP25 quarterly list (articles that have been downloaded the most)

5.      J.Jordaan, R.Zivanovic, “'Frequency Estimation in Power Systems Using the Dynamic Leapfrog Method”, Measurement, Volume 39, June 2006, pp. 451-457

6.      R.Zivanovic, “Local Linear Approximation for Tracking Frequency in Power Systems”, International Journal of Electrical Power & Energy Systems 27 (2005), pp. 409-416

7.      J.A. Jordaan and R.Zivanovic, “Nonparametric Time-Varying Phasor Estimation in Power Systems by using of Non-quadratic Criterion”, Transactions of the South African Institute of Electrical Engineers, March 2004, Vol. 95, No. 1, pp.35-41

8.      R.Zivanovic, P.Schegner, O.Seifert, and G.Pilz, “Identification of the Resonant-Grounded System Parameters by Evaluating Fault Measurement Records”, IEEE Transactions on Power Delivery, July 2004, Vol. 19, Issue 3, pp.1085-1090

9.      R.Zivanovic, “On the Use of Partially Linear Model in Identification of Arcing-Fault Location on Overhead High-Voltage Transmission Lines”, International Journal on Bifurcation and Chaos, invited paper for special issue on Modelling and Identification of Nonlinear Systems, Vol.14, No.6, June 2004, pp. 1975-1985

10.  J.A.Jordaan and R.Zivanovic,” The Application of the Leapfrog Method in Power System State Estimation”, IEE Proceedings Generation, Transmission and Distribution, Vol.150, No.1, January 2003, pp.28-32

Conference Papers

1.      R.Zivanovic and Hoong Boon Ooi, “A Systematic Approach for Testing Transmission Line Fault-Locating Techniques”, Electricity 2007 Conference, The Electric Energy Society of Australia (EESA), 15-17 August Melbourne, Australia

2.      R.Zivanovic and Shuo Chen, “Fault Diagnostics of Induction Machines using Prony Analysis”, paper no. 496, IEEE Power Tech Conference, 1-5 July 2007, Lausanne, Switzerland

3.      R.Zivanovic and Hoong Boon Ooi, “Sensitivity Analysis of Transmission Line Fault Location”, paper no. 498, , IEEE Power Tech Conference, 1-5 July 2007, Lausanne, Switzerland

4.      R.Zivanovic, “Application of Weighted Structured Total Least Squares in Identification of Power System Oscillation Modes”, IEEE PES PowerAfrica 2007 Conference and Exposition, Johannesburg, South Africa, 16-20 July 2007

5.      R.Zivanovic, “Time-Varying Phasor Estimation for Analysis of Digital Fault Records”, 7th International Conference on Power System Operation and Control (ICPSOP’07), 22-24 January 2007, University of Cape Town, South Africa

6.      R.Zivanovic, “An Algorithm for Arcing-Fault Location on Transmission Lines”, Southern African Universities Power Engineering Conference (SAUPEC’07), 25-26 January 2007, University of Cape Town, South Africa

7.      R.Zivanovic, “Estimation of Transmission Line Parameters using Fault Records”, Australasian Universities Power Engineering Conference (AUPEC’06), 10 – 13 December 2006, Victoria University, Melbourne, Australia

8.      A.Ukil and R.Zivanovic, ”Automatic Signal Segmentation based on Abrupt Change Detection for Power Systems Applications”, IEEE Power India Conference, 10-12 April 2006, New Delhi, India

9.      R.Marais, R.Zivanovic, and R.Estment, “Developing a Model to Simulate Least Economic Cost Evaluation of Transmission Expansion Investment”, The 9th International Conference on Probabilistic Methods Applied to Power Systems (PMAPS’06), 11–15 June 2006, Stockholm, Sweden

10.  R. van Heerden, R. Zivanovic and N. Ijumba, “Reclosing on the Alpha-Beta 765kV Line”, Southern African Power System Protection Conference, 8-10 November 2006, Johannesburg, South Africa

11.  A.Ukil and R.Zivanovic, “Application of Abrupt Change Detection-based Signal Segmentation in Power System Oscillation Analysis”, Southern African Universities Power Engineering Conference (SAUPEC’06), January 2006, Durban, South Africa

12.  J.A.Jordaan and R.Zivanovic, “Signal Parameter Estimation in Power Systems: Semi-parametric Spectral Estimation”, Southern African Universities Power Engineering Conference (SAUPEC’06), January 2006, Durban, South Africa

13.  A.Ukil and R.Zivanovic, “Practical Approaches in Application Service Provider: A Comparative Study”, Second World Congress on Lateral-Computing, December 2005, Bangalore, India

14.  A.Ukil and R.Zivanovic, “Application of Abrupt Change Detection in Relay Performance Monitoring”, 40th International Universities Power Engineering Conference (UPEC 2005), University College Cork, Cork, Ireland, September 2005

15.  R.D. Matshidza, R.Zivanovic, “Impact of High Resistance Faults on Impedance Protection Performance”, 18th International Conference and Exhibition on Electricity Distribution (CIRED’2005), Turin, Italy, 6-9 June 2005

16.  R.M. Bukubukwana, R.Zivanovic, “Inrush Current Transients during Energization of an Unloaded Transformer on the ESKOM Network”, 18th International Conference and Exhibition on Electricity Distribution (CIRED’2005), Turin, Italy, 6-9 June 2005

17.  A.Ukil, R.Zivanovic, “Abrupt Change Detection in Power System Fault Analysis using Wavelet Transform”, The 6th International Conference on Power Systems Transients (IPST’2005), Montreal, Canada, June 19-23, 2005

18.  R.Zivanovic, “An Adaptive Median Post-Filter for Impedance Estimation based on Differential Equation Algorithm”, 15th Power Systems Computation Conference 2005 (PSCC’2005), Liege, Belgium, 22-26 August 2005

19.  R. Zivanovic, “Analysis of Recorded Transients on 765kV Lines with Shunt Reactors”, IEEE PowerTech’2005, St.Petersburg, Russia, June 27-30, 2005

20.  R. Zivanovic, “Eliminating Bias in Frequency Estimation based on Prony’s Method”, IEEE PowerTech’2005, St.Petersburg, Russia, June 27-30, 2005

21.  R.Bukubukwana and R.Zivanovic, “Energization of Unloaded Transformers on the ESKOM Network”, 5th Southern Africa Regional CIGRE Conference, Somerset West, South Africa, October 2005

22.  P.Keller, R.Zivanovic and C.Henze, “Support Vector-based Fault Classification on the ESKOM Transmission System”, 5th Southern Africa Regional CIGRE Conference, Somerset West, South Africa, October 2005

23.  T.Wegner, M.Vogelsang, S.Hesse, W.Lazenby and R.Zivanovic, “Estimation of Transmission Line Parameters by Evaluation of Fault Data Records”, Southern African Universities Power Engineering Conference (SAUPEC’05), 27-28 January 2005, University of Witwatersrand, Johannesburg, South Africa

24.  J.Jordaan and R.Zivanovic, “Signal Parameter Estimation in Power Systems: Separable Least Squares vs Newton Methods”, Southern African Universities Power Engineering Conference (SAUPEC’05), 27-28 January 2005, University of Witwatersrand, Johannesburg, South Africa

25.  P.Keller, C.Henze and R.Zivanovic, “Automated Analysis of Digital Fault Records – a Utility Perspective”, Southern African Universities Power Engineering Conference (SAUPEC’05), 27-28 January 2005, University of Witwatersrand, Johannesburg, South Africa

26.  A.Ukil and R.Zivanovic, “Detection of Abrupt Changes in Power System Fault Analysis: A Comparative Study”, Southern African Universities Power Engineering Conference (SAUPEC’05), 27-28 January 2005, University of Witwatersrand, Johannesburg, South Africa

27.  R.Matshidza, R.Zivanovic, N.Ijumba and A.Bartylak, “Analysis of the Dynamic Behaviour of Distance Protection Systems on ESKOM Transmission Networks”, Southern African Universities Power Engineering Conference (SAUPEC’05), 27-28 January 2005, University of Witwatersrand, Johannesburg, South Africa

28.  R.Zivanovic, “A State-Space Signal Decomposition Method for Power System Disturbance Analysis”, Proceedings of the IEEE AFRICON’04 Conference, 15-17 September 2004, Gaborone, Botswana

29.  R.Biernatzki, B.Bitzer, R.Zivanovic, A.D.Els and S.L.Els, “Agent Technology used in Power Systems”, Proceedings of the IEEE AFRICON’04 Conference, 15-17 September 2004, Gaborone, Botswana

30.  R.Zivanovic and P.Schegner, “Pre-filtering Improves Prony Analysis of Disturbance Records”, Proceedings of the Eight International Conference on Developments in Power System Protection, Amsterdam, The Netherlands, 5-8 April 2004, pp.780-783

31.  R.Zivanovic, P.Tlhatlhetji, A.Bartylak and P.Keller, “A Semi-parametric Approach in Arcing Fault Location”, Proceedings of the Eight International Conference on Developments in Power System Protection, Amsterdam, The Netherlands, 5-8 April 2004, pp. 477-480

32.  J.L. van den Berg and R.Zivanovic, “Protection Problems and Solutions Associated with Series Compensated Transmission Lines”, Southern African Universities Power Engineering Conference (SAUPEC’04), 22-23 January 2004, Session Protection and System Automation, paper No.63, University of Stellenbosch, South Africa

33.  A.D. Els, S.L. Els, J.A. Jordaan, R. Zivanovic, “Intelligent Agents Technology For Substation Data Acquisition Systems”, Southern African Universities Power Engineering Conference (SAUPEC’04), 22-23 January 2004, Session Computer Applications, paper No.66, University of Stellenbosch, South Africa

34.  W.H.Lezenby, D.Christensen, R.Zivanovic, “Some Observations on Distance to Fault Calculations, using the Sachdef Algorithm”, Southern African Universities Power Engineering Conference (SAUPEC’04), 22-23 January 2004, Session Renewable Energy Systems, paper No.76, University of Stellenbosch, South Africa

35.  J.A.Jordaan, R.Zivanovic, “Nonparametric Time-Varying Phasor Estimation in Power Systems by making use of Non-quadratic Criterion”, Proceedings of the IEEE AFRICON’02 Conference, October 2002, South Africa, pp.131-136

36.  R.Zivanovic, “A Nonparametric Technique for High Precision Estimation of Power System Time-Varying Phasors”, Proceedings of the 14th Power Systems Computation Conference (PSCC’02), June 24-28, 2002, Sevilla, Spain, Session 37, Paper 1, pp.1-7

37.  R.Zivanovic, “Nonparametric Trend Model for Short Term Electricity Demand Forecasting”, Proceedings of the 5th IEE Conference on Power System Management and Control, 17-19 April 2002, IEE Savoy Place, London, UK, pp.347-352

38.  R.Zivanovic and J.A.Jordaan, “Nonparametric Time-Varying Phasor Estimation in Power Systems”, Southern African Universities Power Engineering Conference (SAUPEC’2002), 31 January – 1 February 2002, Vaal Triangle Technikon, South Africa