ABSTRACT

Narrowband power line communications (NB PLC) technology for frequency between 9 and 500 kHz has been widely used for automatic metering infrastructure (AMI) [1–4]. It is well known that NB PLC for frequency 9–500 kHz subjects to hostile channel conditions. Power line channel at low frequencies is characterised by time-selective and frequency-selective interferences, low access impedances and frequency-selective attenuation [2–8]. Due to negligible cable loss in the low frequencies, the power line channel of access network greatly depends on electrical properties of loads at the network and in particular at customer premises. This dependency is a major source of considerable time variation of power line channel, which makes design of a reliable NB PLC system a challenging task. In China, the influence of electrical appliances in the distribution network and at the customer premises on the performance of NB PLC system is even more evident, partly due to non-strict compliance of electrical appliances with the electromagnetic compatibility (EMC) regulation. To improve the reliability of NB PLC and to enhance its capability to support advanced Smart Grid services, there is still a great need for better understanding of power line channel characteristics in the low frequencies bands.