Abstract: This patent relates to a multi-mode communication method for detecting states of power transmission line, which belongs to electric power communication technology field. In this method, there are sensing devices installed on power transmission line. These sensing devices are used to detect status signals of power transmission line. Status signals are sent to remote monitoring center through communication terminals. Both sensing devices and communication terminals are powered by battery. The main communication network between sensing devices and communication terminals is formed by ZigBee network. Meanwhile, Bluetooth network is a backup communication network between sensing devices and communication terminals. Communication terminals and remote monitoring center are linked through WinMAX.

Abstract: This invention provides a cooperative coverage method for distribution network information perception. The cooperative coverage method includes the following steps: construction of connected cooperative coverage sets, which can cover all target nodes with as few information perception nodes as possible, and maintain the connectivity of each cooperative coverage set with connected sets construction methods based on of hierarchical clustering; Cooperative coverage set scheduling, introducing the concept of energy ratio threshold, dividing the life cycle of the system into multiple time slices, calculating the energy ratio of perception device set in each time slice to realize the set scheduling. The invention realizes the efficient utilization of the energy of the perception device through the construction and scheduling of the connected coverage set in different time slices, and improves the use efficiency of the information perception network.

Abstract: The noise suppression method of individual active noise reduction system comprises the steps that: (1) initial noise digital signals are received and converted to serve as input signals of a BP neural network; (2) the input signals are processed to generate secondary digital signals; (3) the secondary digital signals are output to a loudspeaker and secondary noise is generated; (4) remained noise digital signals obtained by overlapping the initial noise and the secondary noise are received; whether remained noise digital signals is continuously constant for the set times is judged; if yes, the secondary digital signals are kept outputting; (5) if not, BP neural network parameters are optimized and adjusted with the amplitude of the remained noise digital signals being minimum as the optimality principle; remained noise digital signals of previous step are served as new input signals and the step (2) is executed again.