| 摘要 |
Conventional power line communication systems modulate a high frequency carrier, which is superimposed on an electric power grid with a far lower frequency, e.g. 50Hz. However, according to the present invention, data is transmitted by frequency modulating the grid frequency itself. This technique can be applied within a synchronous area of an electric power grid. It is used to transmit a data signal form a transmission device 118 associated with a power device 119, which consumes or provides power to the grid 100. The data is received by a receiver 120 which measures a characteristic relating to a frequency of electricity flowing in the electric power grid, and extracts the data signal based on the measured characteristic. The transmission device may include a power flow modulator arranged to modulate power flow on the basis of a sequence of control signals, thereby provide a corresponding frequency modulation to the grid frequency. The data signals may include identifiers to identify the source or/and intended destination of the data transmission. The receiving device may be provided with a second communications interface, such as a wireless communications interface. |
