A Tool for Phase Spectrum Retrieval from Impedance Amplitude Spectrum

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The estimation of load impedance spectrum is required in the research and applications of electrical engineering. Some of the current applications are the grid impedance estimation of active filters, the research of the propagation of EMI (Electro Magnetic Interference) and power line communication. The direct measurement of load impedance, in the frequency range in question, requires synchronous voltage and current measurement, which can be difficult. Compared to the direct impedance spectrum measurement, the measurement of impedance amplitude spectrum is a simple and low-cost method since e.g. only peak or RMS (Root-Mean-Square) value of current and voltage for each measured frequency is required. This article presents a method and a tool based on the method that allows one to compute the phase spectrum estimate for the impedance amplitude spectrum. The method is based on the maximum entropy model (MEM). The applicability of the tool is demonstrated with input impedance measurements of a low voltage power cable and a low voltage electric motor, where both the amplitude and the phase spectrum of input impedance were measured in the frequency range of 100 kHz – 30 MHz.
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Impedance Measurements; Phase Retrieval; Load Impedance; Active Filters; Power Line Communication; Electromagnetic Interference

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G. Skiblinski G., R. Kerkman, R. Schlegel, EMI Emissions of Modern PWM AC Drives. IEEE Industry Applications Magazine, Vol. 5, Issue 6: 47-80. 1999.

M. Sumner, B. Palethorpe, P. Zanchetta, D. Thomas, Experimental Evaluation of Active Filter Control Incorporating On-line Impedance Measurement, Proc. 10th International Conference on Harmonics and Quality of Power, Vol. 2, 6-9 Oct. 2002, pp. 501-506.

G. Skibinski, R. Kerkman, D. Leggate, J. Pankau, D. Schlegel., Reflected Wave Modeling Techniques for PWM AC Motor Drives, Proc. Applied Power Electronics Conference and Exposition, 1998, Thirteenth Annual, Vol. 2 , 15-19 Feb., 1998, pp. 1021-1029.

L. Tang., P. So, E. Gunawan, Y. Guan., S. Chen, T. Lie, Characterization and modeling of in-building power lines for high-speed data transmission, Power Delivery, IEEE Transactions, Vol. 18, No. 1, pp. 69-77, Issue: 1, Jan 2003.

J. Rhode, A. Kelley, M. Baran, Line Impedance Measurement: A Non-disruptive Wideband Technique, Proc. Industry Applications Conference, Thirtieth IAS Annual Meeting, IAS '95.Volume: 3, Oct. 1995, pp. 2233-2240.

E. Vartiainen., K-E. Peiponen, T. Asakura, Phase Retrieval in Optical Spectroscopy: Resolving Optical Constants from Power Spectra, Applied Spectroscopy, vol. 50, pp. 1283-1289, 1996.

J. Ahola, E. Vartiainen, T. Lindh, Phase Retrieval from Impedance Amplitude Measurement, IEEE Power Electronics Letters, Vol. 3, No. 2, June 2005.

J. Burg, Maximum entropy spectral analysis, Proc. 37th Annual Meeting of the Society of Exploration Geophysicists, Oklahoma City, Oklahoma, 1967.

J. Proakis, D. Manolakis, Digital Signal Processing: Principles, Algorithms, and Applications (Prentice-Hall, Upper Saddle River, New York, 1996).

D. Roessler, Kramers-Kronig analysis of reflection data, British Journal of Applied Physics, Vol. 16, p. 1119-1123, 1965.

J. Ahola, Applicability of Power-line Communications to Data Transfer of On-line Condition Monitoring of Electrical Drives, Ph.D. dissertation, (Lappeenranta University of Technology, Lappeenranta, Finland, 2003).

D. Schlegel, G. Wrate, R. Kerkman, G. Skiblinski, Resonant Tank Motor Model for Voltage Reflection Simulations with PWM Drives, Proc. IEEE International Electrical Machines and Drives Conference, Seattle, USA, 9-12 May, pp. 463-465, 1999.


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