Dragutin Vojković, M.Sc.E.E.


1.1. An analysis of the hydroelectric sets operation in The ČAKOVEC HEPP Part one: Normal operating conditions (Čakovec HEPP, October 1, 1985)

1.2. An analysis of the hydroelectric sets operation in The ČAKOVEC HEPP Part two: Operation with low headrace water levels (ČAKOVEC HEPP, October 23, 1985) 1.3. An analysis of the hydroelectric sets operation in The ČAKOVEC HEPP Part three: Operation with very low headrace water levels (ČAKOVEC HEPP, November 20, 1986)

1.4. A Report on the results of the examination of the turbine and generator protections and their influence on the sequential programs – an emergency stopping (ČAKOVEC HEPP, January 28, 1986)

1.5. An analysis of the electrical protections operation and bulb-type unit emergency stopping evaluation (ČAKOVEC HEPP, February 21, 1986)

1.6. The reconstruction of the sealing assemblages on the generator busbars outlet and the cable outlet from the access shaft (ČAKOVEC HEPP, November 27, 1985)

1.7. The comparison between electrical energy quantities produced in The ČAKOVEC HEPP and The VARAŽDIN HEPP (ČAKOVEC HEPP, October 1985; co-author)

1.8. The measuring and doing sums of the electrical energies in The ČAKOVEC HEPP (ČAKOVEC HEPP, January 1988)

1.9. The operation of the hydroelectric set in The ČAKOVEC HEPP on the isolated network – The preparation for the test (ČAKOVEC HEPP, November 8, 1986)

1.10. The operation of the hydroelectric set in The ČAKOVEC HEPP on the isolated network – The report on the test held on November 16, 1986 (ENERGY INSTITUTE ZAGREB, November 21, 1986; co-authors: M. Mehmedović, Z. Tonković, D. Mihalic)

1.11. The operation of the hydroelectric set in The VARAŽDIN HEPP on the isolated network – The preparations for the test (ENERGY INSTITUTE ZAGREB, January 16, 1989; co-authors have given only data about connection diagrams for measuring equipment)

1.12. Different technical reports Remark: In order to make testing programs for the hydroelectric set working on the isolated network (items 1.9. and 1.11.), I had previously studied as follows: – operating characteristics of particular hydroelectric set (especially the characteristics of the regulation and excitational systems), – system configurations, – substations characteristics, – consumers characteristics, etc. and after that I proposed the best testing methods and lead the tests myself. Both tests have been made succesfully.


2.1.  BOOK OF OPERATING RULES FOR THE ČAKOVEC HEPP – Control instructions for the turbine-generator units, transformers, high-voltage power plants, auxilliary equipment etc. (ČAKOVEC HEPP, 1983)

2.2.BOOK OF RULES FOR MAINTENANCE OF THE ČAKOVEC HEPP – Common part: the organization of the maintenance, the nomenclature of buildings and plants etc. – Professional part: list of works and their incidences for buildings and plants

2.3. A plan of works and money to be invested for a maintenance (for every year)

2.4. A plan of exchanges, reconstructions and modernizings (for every year)

2.5. A plan for repair works on a hydroelectric sets (for every year)

2.6. Designing task for the project of the uniform business and technological systems in ELEKTROPRIVREDA ZAGREB (Zagreb, December 15, 1987; I was the guide of the working group)

2.7. Criterions for the maintenance of HEPP-s in HRVATSKA ELEKTROPRIVREDA – Workers number, costs of the maintenance (Zagreb, 1991) Remark: The papers mentioned above I have made together with my colleagues and my collaborators.


3.1. “Governor RAPID” – technical description (NEYRPIC)

3.2. “Governor RAPID” – Test and trouble-shooting instructions (NEYRPIC, Notice No. 1195, November 14, 1980)

3.3. “Governor RAPID” – Checking of the electric circuits on test-rig (NEYRPIC, Notice No. 1249, June 1975)

3.4. “Vannes aval des 2 groupes bulbes CENTRALE DE ČAKOVEC (NEYRPIC, Notice No. 449.641A, 24 Novembre 1978)

3.5. “Diagramme des Sequences de Fonctionnement d un Groupe – CENTRALE DE ČAKOVEC” (NEYRPIC, Notice No. 482.937 A, 28 Fevrier 1978)

3.6. “Liste des Securites de l Appareillage – CENTRALE DE ČAKOVEC” (NEYRPIC, Notice No. 482.936 E, 25 Novembre 1977)

3.7. ONGE, G.A.St.; HARTY, F.R.; CLICK, J.E.: Start-up, Testing and Performance of the First Bulb-Type Hydroelectric Project in the U.S.A. (IEEE TRANSACTIONS, Vol.PAS-101, No. 6, June 1982, p.p. 1313-1321) Remark: Some papers (items 3.4., 3.5. and 3.6.) I have translated with S. MAČKOVIĆ together.


Since 1982 I took part in solving many different technical problems had occured in the ČAKOVEC HEPP. I am going to point out only o few of them:

4.1. Overheating of generator busbars cubicles

4.2. Overheating in an oil system when a failure of cooler occured

4.3. Noise suppression in the machine house

4.4. Development of some measuring circuits

4.5. A failure in the excitational system of the generator

4.6. A failure in the insulating system of stator windings

4.7. Water leakage through concrete walls and mending

4.8. Control system reconstruction


5.1. D. Vojković: Computation of short circuit currents in the three phase bridge rectifier connection (INFORMATICA 74 – Bled, 4.1. pages 1-10)

5.2. B. Franković, Z. Petrinović, Z. Pletikapić, D. Vojković, S. Vučić: Small-scale hydroelectric power plants incorporated into low-head diversion-canal type hydroelectric power plants (Proceedings of the 2-nd Polish – Yugoslav Symposium, Begovo Razdolje, September 1986, pages 193-210)

5.3. D. Vojković, D. Magić, Ž. Logarić, S. Bagić, B. Horvat: Supervision, control and regulation at the superposed level in The ČAKOVEC HEPP (RADE KONČAR ZAGREB, 1987.)

5.4. D. Vojković, Z. Periša-Marinčić, V. Brentin, P. Marinčić: The thyristor rectifier for a generator winding drying (The fifth International Consultation on the Electric-motor Drives, Poreč, 1990)

5.5. D. Vojković: An Operational Experience with the Bulb Type Units in the ČAKOVEC HYDROELECTRIC POWER PLANT (The Professional Consultation “An improvement of Hydroelectric Power Plants Exploitation”, Brioni, 1989)


6.1. V. Kovačić, D. Vojković: An analysis of power oscilations of the generator sets in the DUBRAVA HEPP on the basis of the previous measurings and study works (ELIT d.o.o. Čakovec, July 2013., the paper presented to the specialists with HEP – PROIZVODNJA d.o.o., PP HE SJEVER Varaždin, on the 17.10.2013.)