| In recent years,new energy vehicle industry has developed rapidly in China.As a major country of new energy industry,the Chinese government is also vigorously supporting the development of new energy industry,but Chinese current new energy vehicle charging infrastructure construction is still lagging behind.At present,most of Chinese new energy vehicle charging facilities are built in densely populated areas,while unattended photovoltaic charging stations provide a good solution to the problem of new energy vehicle charging in remote areas.In the unattended photovoltaic charging station,due to the difficulty of personnel maintenance,the hidden trouble of cables in the unmanned charging station due to the environment and many other factors has to attract people’s attention.So this design to the problem of unattended photovoltaic cable fault in the charging station based on chaotic spread spectrum domain detection design of charging station for unattended photovoltaic cable detection system,to facilitate the cable failure in a timely manner to determine which cable fault location for cable maintenance,ensure the normal operation of the photovoltaic charging stations.Mainly complete the following work:1.According to the composition of the cable detection system in the unmanned photovoltaic charging station,the model construction of the cable detection system in the unmanned photovoltaic charging station is completed,and the application of chaotic sequence in the chaotic extended spectrum time domain detection method is simulated and verified.2.Through the demand analysis of the unattended photovoltaic charging station cable detection system,the design of each module of the unattended photovoltaic charging station cable detection system has been completed.Based on FPGA,chaotic sequence generation module,BPSK modulation module,DA transmitting module,AD acquisition module and BPSK demodulation module are designed.Perform functional simulation of each module and perform backplane verification.3.The generalized cross-correlation algorithm in the application of chaotic SSTDR method has carried on the simulation analysis,three kinds of commonly used in the generalized cross-correlation algorithm of weighted function in the chaotic spread spectrum comparison of computation results of time domain reflection method,it’s found that the generalized cross-correlation algorithm using the SCOT weighting function is not only better than the basic cross-correlation algorithm,but also better than the generalized cross-correlation algorithm using the other two commonly used weighting functions.It is verified that the cable detection system model of unattended photovoltaic charging station designed in this paper has met the expected requirements for chaotic sequence generation,DA emission,AD acquisition and other functions.The generalized cross-correlation algorithm is better than the basic cross-correlation algorithm when applied to the chaotic spread-spectrum time-domain reflection method.This design is meaningful for the research of unattended photovoltaic charging station cable detection system. |
