Abstract: The occurrence of a large disturbance in a power system can lead to a decline in the system frequency and bus voltages due to a real and reactive power deficiency or due to the formation of islands with generation–load imbalance. Load shedding is a last line of control action that can prevent a blackout in the power system by relieving the overload in some parts of the system. This paper describes a new algorithm for load sheding under emergency condition to avoid risk of voltage instability. For this purpose minimum eigen value of load flow Jacobian has been selected as proximity indicator, which is obtained using continuation power flow methodology. The amount of load to be shed is decided by sensitivity index so as to maintain a threshold value of proximity indicator and all load bus voltages within limit. Sensitivity of indicator with respect to load (real & reactive power) to be shed has been used to rank the load buses and, simultaneously minimize the computation time and amount of load to be shed. Higher order load buses are selected for load sheding to avoid voltage collapse problem in stipulated time to maintain the reliability of the supply system. Developed algorithm has been implemented on a IEEE 14-bus system, 20-line test system.
Keywords: Load shedding, voltage instability, minimum eigenvalue, sensitivity index and continuation power flow.
Title: Load Shedding Based on Sensitivity Index to Avoid Voltage Collapse
Author: Bharti Pandey, Dr L S Titare
International Journal of Electrical and Electronics Research
ISSN 2348-6988 (online)
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