Detection of Fault Location in Active Distribution Network by Hybrid State Estimation

Generation and load are increasing gradually; distribution systems are facing additional complications with the increase in load demand and incorporation of distributed generators. The inactive distribution systems getting changed into active distribution systems. Nowadays, identifying faults becomes tough job and causes a lot of inconvenience to consumers. Therefore, there is a need for a real-time model to monitor the distribution networks. State estimation can be an effective method to build realistic models, mainly for nonlinear and highly unbalanced systems like the distribution grid. This paper presents hybrid state estimation which has nonlinear state estimation using Remote Terminal Units data and linear state estimation with the optimal number of Phasor Measurement Units data in an active distribution networks. The occurrence of Fault in the system is identified whenever the change in voltage at any bus is more than change in voltage threshold value at that bus. Further, faulty section has been identified by observing voltage profile obtained from linear state estimation procedure. IEEE 33 bus test system taken for validation of results.