Research On SF₆ Leak Detection Method Based On Differential Absorption Radar

With the development of economy,electric energy has become the most important part of social life and production,and there is always leakage problem of SF₆ insulating gas in high and medium voltage power equipment.Aiming at the problem of low on-line detection accuracy of existing SF₆ gas,a SF₆ leak detection method and system based on differential absorption lidar is proposed and AJAFSA-SVM temperature compensation algorithm is added to the system.In this paper,the theoretical basis of differential absorption laser radar and the absorption and absorption cross sections of SF₆ molecules are analyzed firstly.The feasibility of differential absorption laser radar technology for detecting SF₆ gas is theoretically verified.Secondly,the differential absorption laser radar system is simulated to detect the measurement accuracy of the system when the leakage concentration is different,and plot the measured value and measurement error value.Verification shows that the differential absorption lidar system has higher detection accuracy.For the problem that the system has too large measurement error when the ambient temperature is too low?<5°C?or too high?>25°C?,the SVM algorithm is used for temperature compensation.The selection method of penalty factor C and Gaussian kernel function?in the existing SVM algorithm has the problems of low precision,long selection time and difficulty in obtaining the optimal value.This paper proposes to use AJAFSA algorithm to optimize the above two parameters.The algorithm dynamically changes the field of view and step size based on AFSA,adds global information to the location update,and optimizes the parameters in the SVM algorithm with the improved AFSA algorithm.The experimental results show that compared with the AFSA-optimized SVM algorithm,the training time of the proposed algorithm is shortened by 35.300s,the test time is shortened by 0.657s,and the test extreme difference is reduced to 49,which is the previous 60.49%,and the performance of the algorithm is optimized.The improved algorithm is applied to the SF₆ concentration test.The experimental verification shows that the temperature error compensated SF₆concentration test system has the measurement error value within the allowable range,which reflects the necessity of temperature compensation.