Adaptive Under Frequency Load Shedding By Considering Voltage Deviation and STATCOM

The last step to prevent the collapse of the power system and the frequency control operation from stabilizing during disturbances is under frequency load shedding operation. This operation is performed according to some data such as voltage, frequency, or a combination of those. There are two under-frequency load-shedding methods, centralized and decentralized. In a centralized approach, buses data such as voltage and frequency are sent to a control centre, and a special algorithm carries out a UFLS operation within the central processor of the control centre. However, in the non-centralized method, relays are performed using an algorithm that has been used for frequency relays, and they are beginning to perform UFLS operation. In this paper, the proposed method tries to identify the load location disconnected from the power grid. On the other hand, the process introduced in this paper attempts to restore the frequency of power system by a decentralized method using data relays. to test this method, a 39-bus IEEE standard system is utilized and compared with conventional methods. Numeric simulation in this paper has been carried out by MatLab and Digsilent powerfactory.