Study of a New Time Transfer Method of Low Voltage Power Line

Time transfer technology plays an important role in time science. With the development of communication, the time transfer technique has made significant evolving. The precision has got improved greatly and the application of the time and frequency has extended. The electric power network distribute widely, forming the general network for power energy transmitting and communication. The advantages of communication and time code transfer utilize the low voltage power line (LVPL) are: (1) the communication signal and power energy transmitting are using the same cable; (2) The devices are low in price and the techniques are applied widely. (3) The configuration of the device are simple, stable and convenient installment, and (4), persistent connection. This paper investigates the characteristic of the noise and attenuation of LVPL channel. To analyze the characteristic of signal transmitting in LVPL, the linear frequency modulation in spread spectrum communication is chosen according to the current techniques of the LVPL in data communication. A novelty method for LVPL time transfer is also presented. To demonstrate the performance of the new method, the experiments were conducted using two low voltage power lines with the lengths of 50 meters and 5 meters respectively, the results indicate that the corresponding time synchronization precision is less than 10 microseconds. The precision satisfy the general users and can be used to supply time synchronization service to scientific research, auto-control and power grid etc.