Renewal of Middle Wave Transmitters in Slovak Republic
DOI:
https://doi.org/10.22213/2413-1172-2021-4-65-72Keywords:
middle wave transmitters, antennas, impedance matching, lightning strike protectionAbstract
This paper deals with the replacement of middle wave transmitters in Slovak Republic. The original transmitters were based on class C vacuum tube fundamentals and were produced by the Czechoslovakian group company Tesla. Class C transmitters were transmitting reliably to this day, however, the lifespan of these transmitters was nearing its end, moreover the need for a better quality analog modulated signal has pushed for its replacement and therefore they were replaced by modern, highly efficient class D transmitters, while utilizing the original infrastructure consisting of antennas and power inputs. Due to differences in characteristic parameters, however minor, this caused some significant problems, with impedance matching. To resolve these problems, it was necessary to implement a newly designed IMU (Impedance Matching Unit), while also securing a lightning strike protection. This paper has proposed a possibility of lightning surge protection of middle wave transmitters. The original protection implemented with the installations of class C transmitters was consisted only of multiple spark gaps. This kind of protection may prove inefficient using new class D transmitters. The device described in this paper has been designed and successfully implemented on a middle wave transmitter in Čižatice. This transmitter is transmitting with 5 kW power on the antenna with the carrier frequency of 702 kHz. Since the implementation of our device, the transmitter reports no failures and continues to transmit safely.References
Eloch M. Performance of surge arrestors under single and multiple lightning impulses. International Symposium on Lightning Protection, XIV SIPDA 2017, no. 8116920, pp. 176-182. DOI: 10.1109/SIPDA.2017.8116920.
Gomes Ch., Galvan A. Lightning protection scenarios of communication tower sites; human hazards and equipment damage. Article in Safety science, December 2011, pp. 1355-1364. DOI: 10.1016/j.ssci.2011.05.006.
Podporkin G.V., Wetter M., Heckler H. Surge-protective devices. Lightning Interaction with Power Systems, Scopus, 2020, pp. 287-343.
Ngampradit V. Discussion on measured impulse sparkover voltage of Gas Discharge Tubes (GDT). 30th International Conference on Lightning Protection 1, 2017, art. no. 7845884.
Hodzic M., Mujcic A., Suljanovic N., Zajc M. Modelling Overvoltage Protection Components: Verilog Simulations of Combined MOV and GDT Arresters. Journal of Microelectronics, Electronic Components and Materials, 2017, vol. 47, no. 4, pp. 261-71.
CITEL BE 800 Technical documentation. https://citel.de/en/gdt/gsg/be-800 [accessed 9.11.2021].
Bittera M., Hallon J. Directivity of capacitive clamp for EFT pulses injection. Institude of Electrical Engineering, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Bratislava, Slovak Republic, April 2014, Bratislava. DOI: 10.1109/Radioelek.2014.6828459.
Harťanský R., Maga D., Ješko V. Elektromagnetická kompatibilita v mechatronických systémoch. Trenčianska univerzita v Trenčíne, Jilemnického, Trenčín, September 2000. ISBN 80-88914-22-1.
Pivarčiová E., Sobrino D.R.D., Nikitin Yu.R., Holubek R., Ružarovský R. Measuring and Evaluating the Differences of Compared Images for a Correct Car Silhouette Categorization using Integral Transforms. MEASUREMENT SCIENCE REVIEW, 2018, vol. 18, no. 4, pp. 168-174. DOI: 10.1515/msr-2018-0024.
Rakov A.V. Transient Response of a Tall Object to Lightning. IEEE Transactions on electromagnetic compatibility, 2001, vol. 43, no. 4, pp. 654-661. DOI: 10.1109/15.974646.
Principles of protection against overvoltages and ovecurrents. Telecommunication standardization sector of ITU. Geneva, 2010, Switzerland.
Lightning and surge protection - basic principles. COURSE-HINDS series, EATON Electric Limited, October 2016.
Ondráček O. Signály a sústavy. Vydavateľstvo STU, Slovenská Technická Univerzita, Bratislava, 2008, 341 p. ISBN 9788 0227 29567.
Savage E.B., Radasky W.A. E1 HEMP Test of Gas Discharge Tube Surge Protectors for HF Radios. 2019 IEEE International Symposium on Electromagnetic Compatibility, Signal and Power Integrity (EMC + SIPI). New Orleans, LA: IEEE, EMC Soc. Jul 22-26, 2019. ISBN 978-1-5386-9199-1.
Zhang Y., Zhang W., Ji J. Study of a Combined Surge Protective Device for a Relay Protection Circuit in a UHV Converter Station, 2020. DOI: 10.1109/ACCESS.2020.3020374.
Wang D., Gao L. Investigation on the Surge AbsorbsionCapabilitioes of Multi-stage and Single Stage RF LEMP protection Modules. 2017 IEEE Electrical Design of Advanced Packaging and Systems Symposium (EDAPS), Dec. 14-16. DOI: 10.1109/EDAPS.2017.8276912.
Wang D., Gao L. Experimental research on multiple stages EMP protection measure for HF transmitter. Proc. of the 11th International Symposium on Antennas, Propagation and EM Theory, 2016, no. 7834024, pp. 592-594. DOI: 10.1109/ISAPE.2016.7834024.
Qinghua C., Lixia Y., Shu Y. Ungrounded Lightning Surge Protection Device for Wireless Sensor Networks Node in the Wilderness, Conference: 2018 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC), July 2018. DOI: 10.1109/CSQRWC.2018.8455701.
Buhrym I., Vynokurov O., Galkin P. Approaches to Designing a Wireless Sensor Network Node. Theoretical and Applied Aspects of Device Development on Microcontrollers and FPGAs. Jan., 2019. DOI: 10.35598/ mcfpga.2019.007.
Zhang H. Wireless sensor network node sleep scheduling algorithm. Journal of Physics Conference Series, 1976(1):012038. July 2021. DOI: 10.1088/1742-6596/1976/1/012038.
