The Transmission Of Locomotive Control Signal Based On Power Line Communication

Power line communication uses power line as communication media for data transmission and information exchange. With the advancement of the technologies of modulation, transmission and signal procession, power line communication is developing all the way: Multi-carrier modulation substitutes for single carrier modulation and data rate increases from a few Kilobits to several Megabits. At present, power line communication comes into an era developing with high speed. Because power line communication has several advantages, such as no need of new wire and low cost, it has drawn a lot of attentions in many kinds of fields. Orthogonal Frequency Division Multiplexing(OFDM) is a critical technology for the realization of broadband power line communication. It is a type of multi-carrier modulation and a technology of multiplexing. OFDM utilizes several sub-carriers which are orthogonal with one another to transmit information, thus, the utilization of frequency band is enhanced greatly and the frequency selective fading and time variation in power line channel can be overcome effectively. The reliable data communication with high speed has been realized.The purpose of this thesis is to realize the transmission of locomotive control signal by using the technology of power line communication. As in the locomotive lo-control system, data of control signal can be transmitted from the master control locomotive to the sub-locomotive through the overhead contract system. This thesis analyzes the noise effect of medium voltage power line, and introduces the electromagnetic affection towards data communication that caused by the 25 kilo voltage overhead contract system. Then through the comparing of several traditional methods of modulation technology, the OFDM is chosen to be the usable technology. In order to deepen the comprehension of OFDM, this thesis introduces the principle of OFDM briefly, analyzes the advantages and disadvantages to apply OFDM in power line communication. At last, the thesis introduces a suit of power line digital transceiver module KQ-100K, and also made an experiment to prove the feasible of this plan. The experiment realized data transmission based on 220 voltages in our lab. It will contribute a lot for future development.