Simulation of Static Frequency Converter for Synchronous Machine Operation and Investigation of Shaft Voltage
This study is carried out to understand the effects of Static frequency converter (SFC) on large machine. SFC has a feature of four quadrant operations. By virtue of this it can be implemented to run a synchronous machine either as a motor or alternator. This dual mode operation helps a single machine to start & run as a motor and then it can be converted as an alternator whenever required. One such dual purpose machine is taken here for study. This machine is installed at a laboratory carrying out short circuit test on high power electrical equipment. SFC connected with this machine is broadly described in this paper. The same SFC has been modeled with the MATLAB/Simulink software. The data applied on this virtual model are the actual parameters from SFC and synchronous machine. After running the model, simulated machine voltage and current waveforms are validated with the real measurements. Processing of these waveforms is done through Fast Fourier Transformation (FFT) which reveals that the waveforms are not sinusoidal rather they contain number of harmonics. These harmonics are the major cause of generating shaft voltage. It is known that bearings of electrical machine are vulnerable to current flow through it due to shaft voltage. A general discussion on causes of shaft voltage in perspective with this machine is presented in this paper.
Keywords: Simulation, Synchronous Machines, Fourier Transforms, Inductive Coupling, electric discharge machining, Frequency Converter, thyristor, Capacitive coupling, Shaft voltage, Alternators, AC-DC power conversion, static excitation
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1091990Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5424
 A. Hisanori Taguchi, et al., "APS Control Method for Gas Turbine Startup by SFC”, International Power Electronics Conference, pp.264-269 IEEE, 2010.
 Shin-Hyun Park, Seon-Hwan Hwang, Jang-Mok Kim, Ho-Seon Ryu, Joo-Hyun Lee, "A Starting-up control algorithm of large synchronous generation motor for Gas Turbosets”, IEEE International Symposium on Industrial Electronics ISIE, pp.502-508, 2008.
 Zhang Yu-Zhi, "Study of Process of Starting Pumped Storage Machines by Static Frequency Converter with Field Current Controlled”, International Conference on Signal Processing Systems, pp. V1-224 –V1-227, IEEE2010.
 Robert B., Fisher, P.E., "Introduction of Static Frequency Converters on SEPTA’s 25Hz Commuter Rail System”, pp.149-155, IEEE.
 Datta A. K., Manisha Dubey, N. R. Mondal, B. V. Raghavaiah, "Motor-less operation of Short Circuit generator – A CPRI Perspective”, International Conference on Electrical Power and Energy Systems (ICEPES-2010), pp.439-445, 26-28 August 2010 MANIT, Bhopal.
 Datta Arun Kumar, Ansari M. A., Mondal N. R., Raghavaiah B. V. "A Novel Use of Power Electronics: Prime Mover-less Alternator with Static Drive & Excitation System” International Journal of Electronics & Communication Technology, Vol. 3, Issue 1, pp. 472-475, January - March 2012.
 Arun Kumar Datta, G. Venkateswarlu, J. R. Gajbhiye, "Excitation Control in Motor Mode of Short Circuit Generator”, All India Conference on Environmental Impact of Electrical & Electronics Engineering (AICON’12), pp.31-34, 20-21 Jan 2012, CSIT, Durg.
 L. J. Lane, D. F. Rogers, P. A. Vance, "Design and Tests of a Static Excitation System for Industrial and Utility Steam Turbine-Generators”, pp.1077-1085, A.I.E.E., 1962.
 R.C. Schaefer, "Applying Static Excitation Systems”, pp. 41-49, IEEE Industry Application Magazine Nov/Dec1998.
 Tsorng-Juu Liang, et al, "Analysis of 12 Pulse Phase Control AC/DC Converter”, IEEE 1999 International Conference on Power Electronics and Drive Systems, PEDS'99, pp.779-783, July 1999, Hong Kong.
 Datta Arun Kumar, Dubey Manisha, Jain Shailendra, "Study of shaft voltage & bearing currents in electrical machines," IEEE Students' Conference on Electrical, Electronics and Computer Science (SCEECS), pp.1-4, 1-2 March 2012.
 C. Ammann, K. Reichert, R. Joho Z. Posedel, Shaft Voltages in Generators with Static Excitation Systems - Problems and Solution, IEEE Transactions on Energy Conversion, pp.409-419, Vol. 3, No. 2, June 1988.
 Sidney Bell, Timothy J. Cookson, Steven A. Cope, Richard A. Epperly, Annika Fischer, David W. Schlegel, and Gary L. Skibinski, "Experience with variable-frequency drives and motor bearing reliability”, IEEE Transactions on Industry Applications, vol. 37, no. 5, pp.1438-1446, September/October 2001.
 S. Chen, T. A. Lipo, and D. Fritzgerald, "Measurement and analysis of induction motor bearing currents in pwm inverter drives”, Research report 95-20, June 1995, IEEE Summer Power Meeting, July 1995.
 J. Erdman, R. J. Kerkman, D. Schlegel, and G. Skibinski, "Effect of PWM inverters on AC motor bearing currents and shaft voltages,” IEEE Transaction on Industrial Application, vol. 32, pp. 250–259, Mar./Apr. 1996.
 Shaotang Chen, T. A. Lipo, "Circulating Type Motor Bearing current in Inverter Drives”, - IEEE Industry Applications Magazine, pp. 32-38, January/February 1998.
 Muetze A. and Binder A., "Calculation of circulating bearing currents in machines of inverter-based drive systems", IEEE Transactions on Industrial Electronics, vol. 54, no. 2, pp. 932-938, April 2007.
 Muetze A., "On a new type of inverter-induced bearing current in large drives with one journal bearing” IEEE Transactions on Industry Applications, vol. 46, no. 1, pp.240-248, January/February 2010.
 Fei Wang, "Motor shaft voltages and bearing currents and their reduction in multilevel medium-voltage PWM voltage-source-inverter drive applications”, IEEE Transactions on Industry Applications, vol. 36, no. 5, pp.1336-1341, September/October 2000.
 M. R. Baiju, K. K. Mohapatra, R. S. Kanchan, and K. Gopakumar, "A dual two-level inverter scheme with common mode voltage elimination for an induction motor drive”, IEEE Transactions on Power Electronics, vol. 19, no. 3, pp. 794-805, May 2004.
 Hirofumi Akagi and Takafumi Doumoto, "An approach to eliminating high-frequency shaft voltage and ground leakage current from an inverter-driven motor” IEEE Transactions on Industry Applications, vol. 40, no. 4, pp. 1162-1169, July/August 2004.
 R. S. Kanchan, P. N. Tekwani, and K. Gopakumar, "three-level inverter scheme with common mode voltage elimination and DC link capacitor voltage balancing for an open-end winding induction motor drive," IEEE Transactions on Power Electronics, vol. 21, pp. 1676-1683, 2006.
 Akagi, H.; Isozaki, K.; "A hybrid active filter for a three-phase 12-pulse diode rectifier used as the front end of a medium-voltage motor drive", IEEE Transactions on Power Electronics, vol.27, no.1, pp.69-77, Jan. 2012.
 Zhao, Z.; Zhong, Y.; Gao, H.; Yuan, L.; Lu, T.; , "Hybrid selective harmonic elimination PWM for common-mode voltage reduction in three-level neutral-point-clamped inverters for variable speed induction drives," IEEE Transactions on Power Electronics, vol.27, no.3, pp.1152-1158, March 2012.
 Yuen, K. K.-F.; Chung, H. S.-H.; Cheung, V. S.-P.; , "An active low-loss motor terminal filter for overvoltage suppression and common-mode current reduction" IEEE Transactions on Power Electronics, vol.27, no.7, pp.3158-3172, July 2012.
 Zhu, N.; Xu, D.; Wu, B.; Zargari, N. R.; Kazerani, M.; Liu, F.; , "Common mode voltage reduction methods for current-source converters in medium-voltage drives,", IEEE Transactions on Power Electronics, vol.28, no.2, pp.995-1006, Feb. 2013.
 Arun Kumar Datta, Manisha Dubey, Shailendra Jain, "Study of Shaft Voltage on Short Circuit Alternator with Static Frequency Converter”, International Journal of Electrical, Electronic Science and Engineering, World Academy of Science, Engineering and Technology (WASET) pp. 692-698, Vol.7 No.11, 2013.
 Datta Arun Kumar, Dubey Manisha, Jain Shailendra, "Investigation of bearing currents in dual mode operation of synchronous machine with static excitation system," pp. 45-53, Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 2, No 4, November 2013.
 The MathWorksTM, Inc., USA, Release 2008a (R2008a).
 Tore Peterson, Kjell Frank,"Starting of large synchronous motor using static frequency converter”, paper 71 TP 519-PWR for IEEE International Symposium on High Power Testing, Portland, Ore., pp.172-179, July 18-23, 1971.
 Tian Hua Liu, et al.,"Modeling and Harmonic Elimination for a Static Frequency Converter Driving a 300 MVA Synchronous Machine”, pp.602-607, IEEE, 1996.
 Ho-Seon Ryu, et al "A Study of Synchronous Motor Drive using Static Frequency Converter” EPE-PEMC, pp.1496-1499, 2006, IEEE.
 Datta A. K., G. Venkateswarlu, M. A. Ansari, N. R. Mondal, "Excitation Control during Short Circuit Test Sequence of 1500 MVA Short Circuit Generator”, International Conference on Advances in Computer, Electronics & Electrical Engineering (ICACEEE-2012), pp.207-211, 25-27 March 2012 Mumbai.