Faults detection and classification of HVDC transmission lines of using discrete wavelet transform

Now a days HVDC Transmission System are being used due to its advantage over HVAC Transmission systems based on several features like minor Transmission losses, efficient control of Electric power flow, stability and very economical for long Transmission lines. Transmission Line having length of several kilometers and located in open environment for this fault occurring chances are very high as compared other part of power system. These faults have several effects, its necessary to detect and classified these faults within very short time for safe operation of power system. This paper presents the solution of fault detection and classification of overhead HVDC Transmission lines by applying Discrete Wavelet Transform (DWT). Faults in HVDC Transmission line of several types have been created using MATLAB/Simulink. The current signals of HVDC Transmission Lines are attained from Current Transformer and Scope block in work space, and then decompose by means of DWT to obtain the details coefficients up to three levels. Furthermore, Norm of detail coefficient at 3rd level is calculated. To detect and Classification the faults on HVDC Transmission lines Value of Norm are compared with threshold values of the system. The proposed approach has been successfully tested for various types of faults at different line location.