Characteristics of 440V power-line channels in container ships

Control and monitoring is a promising application of power-line communications (PLC) in cargo-carrying ships. The container ship studied in this paper is a type of cargo-carrying ships. The reefer containers on the container ship have been monitored by using PLC over the three-phase 440 V line. Since not only reefer containers but also a lot of equipment are connected to the three-phase 440 V electric power-line, the obtained speed and quality of the PLC system have been so poor that improvement had been required. To improve the performance, the introduction of the wideband PLC technology is considered in this paper because the conventional PLC system is based on the narrowband PLC technology. There are few reports which describe the channel characteristics of cargo-carrying ships. Although the authors had been measuring the characteristics of 100 V lines in the ships since 2007, the characteristics of 440 V lines had not measured as yet. In this paper, the measurement results of the transmission characteristics in three-phase 440 V electric power-lines of the container ships are explained and modeled. Two transmission modes, differential and common, were examined in the measurement. The results show that it will be possible to perform stable and high -speed PLC systems over long distances using the 3 phase 440 V power-line of cargo ships if the differential transmission mode will be used.