Investigation into the impedance and communication requirements for the low voltage distribution line in the high frequency spectrum

• Main Author: Haq, Tanzirul
• Format: Dissertation
• Language: English
• Published: Open University 2012
• DOI: 10.21954/ou.ro.0000d4fe

Power Line Communications is long established for low data rate applications over high- voltage power lines. It is now charting new territory in high speed data transmission to the high frequency band of IMHz and upwards over the low-voltage segment below the distribution transformers.' Since the power line is designed for transmission of power instead of signal transmitting originally; it has many shortages when used as a signal communication channel. The heterogeneous structure of the power line network with numerous branches and impedance mismatche~ causing reflections and attenuations during signal transmission, and thus communication signal cannot be sent out or received completely. From this point of view, the power line impedance is a very important parameter in the design of power line communication (PLC) modem architecture, which is subject to legislations that limit the signals in the line. Variations on the impedance of the power line affect the communications channel performance. For the optimum modem design, power line impedance must be known. Power line impedance changes with time, carrier frequency, load variations, architectures and locations of the lines in city, urban, rural & industrial environment. The objective of this study is to determine the impedance of power distribution network in a frequency range from IMHz to 30MHz. This is in line with international standard bodies including CENELEC, IEC, ITV and ETSI, which stipulates that for propagation characteristics of power line and EMC regulations, data transmission rate are evolving and . are being extended all the time to data rate up to lOOMbps.