Locational bias to frequency linked Unscheduled Interchange (UI) pricing in India

The Unscheduled Interchange (UI) mechanism has been introduced in India to control frequency of the grid in a tighter band and thereby achieve the grid security. The current UI mechanism does not accommodate the losses and certain issues arise because of this. Inclusion of loss factor into the UI curve indicates providing a locational bias to the existing UI curve. This work proposes provision of locational bias to UI curve using different loss allocation techniques. The objective of balancing UI account settlement is achieved. Methods like Proportionate Sharing Principle (PSP), Physical Flow (PF), Incremental Transmission Loss (ITL) coefficients, Z-Bus are used for the said purpose. The simulations have been carried out on IEEE 30 bus system to establish the concept. Further, results on practical system of Western Regional (WR) grid of India have been obtained. Historic data of WR grid has been used for the said purpose.