International Research Journal of Education and Technology

There is a significant difference in fault detection technique of series compensated transmission line during normal operating condition and power swing condition due to several reasons like frequency modulation, sub-harmonic oscillations, transients etc. Especially during power swing condition the frequency of power change is modulated and it is twice of frequency of voltage change and current change. So, cycle to cycle or sample to sample comparison is not reliable here. Other techniques like Voltage Change, Current Change or Impedance change methods are also not applicable during power swing condition. Further inclusion of capacitor in transmission line evokes transients and sub-synchronous resonance activity in series compensated line. So, fault detection during power swing. condition in case of series compensated line is extreme difficult. In this project a method is developed to detect fault of series compensated transmission line during power swing condition. Further the study carried out to identify the proper location and Classification and estimated zone of the fault. Then the study is carried on to identify the exact phase of the fault and how to improve the accuracy of the obtained results by using different types of low pass filter. Each study is carried out on a SMIB and a WSCC-3- Machine-9 bus system with different contingency combinations and by varying different Parameters of the system and the result are listed. The results are available in terms of graphs, figures and tables. Here it proposes a negative-sequence current based technique for detecting presence of fault, classification of fault occurred, estimated zone and location of the fault occurred and the fault inception time with respect to system reference clock during the power swing condition in a series compensated line. In proposed work negative sequence current was analysed as it keeps the other parameters in the system in healthy state. The proposed approach is a cumulative sum (CUSUM) of change in the magnitude of the negative-sequence current-based approach. The task of series compensation is to reduce the transmission lines inductivity. Means, the line length is virtually shortened.