The Study About Quality And Networking Modes Of Low Voltage Power Line Carrier Communication

There is always accessing to some load in low-voltage power line communications. Now commonly used appliances are used the switch type Dc regulated power supply such as computer, TV, the input end of the switching power supply fixed with filters, all the power input end of the filers all in parallel with a capacitance which its capacitance resistance is less than 0.1uF. When the signal transmission in low-voltage networks, the capacitance of the impedance presented to the carrier for 1/ωC, while ω is the carrier angular frequency and C is the capacitance value. These small capacitors and power lines are combined to form a number of the resonant circuits. They forming a low-impedance region nearby the frequency and the resonance frequency, and therefore, there will have a lot impedance downturn-area in the impedance frequency characteristics. The input impedance of the power line change very strongly with different frequency, which resulted that low voltage power line communication quality, is not ideal, this paper analyzes this problem.This paper outlines development process of power line carrier communication, as well as the research and current situation which made by power line carrier communication at home and abroad. To analysis of the communication channel impedance and attenuation characteristics of low-voltage power lines, and to establish ideal equivalent circuit of electric power lines based on transmission line theory. To analysis of the impedance characteristics of power line carrier communication as well as the influence in the quality of communication after the low-voltage distribution network access appliances. The study found that low voltage power line carrier communication quality is more worse with the increase in the number of electrical equipment, but when the number of electrical equipment over five, the rate of signal attenuation reduce. This paper determine the best carrier frequency of low-voltage power line carrier communication is 50KHz～70KHz, which suitable the situation in interference of multi-use appliances.To make the entire low-voltage distribution network’s data can be transmitted more quickly, to realize the distribution network’s broadband access, the key is to ensure that the connectivity and stability of data between each link and each node in network, enabling the entire low voltage power line carrier communication well runs. This paper analyzes the characteristics of ant colony algorithm, and applied the idea of ant colony algorithm to the power line networking. To optimize the selection of route about power line carrier by ant colony algorithm, and to analyze the feasibility of ant colony algorithm for solving the routing aspects of optimization. To performed simulation analysis by Matlab, and analyzed the speed and stability of ant colony algorithm in route optimization.