Ancillary services management in deregulated hybrid power system with significant wind power

Abstract

The main function of power system is to deliver quality power to its consumers. In addition to this, some additional but essential services are required by power system to maintain its secure and reliable operation. These services are termed as ancillary services. With deregularization of power system and increasing share of renewables, it becomes necessary to define ancillary services in a separate and different way. In this thesis, an attempt has been made to propose effective and economic solutions for major ancillary services management in wind integrated deregulated power system. For load frequency control, effect of frequency liked pricing scheme has been studied, under the influence of either DFIG based wind unit or energy storage devices for frequency, tie-line power and voltage control for combined model of ALFC and AVC loops. For reactive power management, reactive power cost model has been proposed that includes cost of reactive power in terms of lost spinning reserve cost and lost opportunity cost of bidding real power into power market. This cost effective model is thereby used to do financial comparison of power system integrated with fixed speed wind plant and DFIG based variable speed wind plant. For congestion management, a rescheduling based novel combined bidding strategy for hydro-wind combination has been proposed, considering secure bilateral transactions between Gencos and Discos. This strategy is based on power imbalances caused by wind units due to difference in their scheduled power and actual power delivered. These power imbalances are reduced by coordinated operation of hydro-wind combination. The proposed strategy provides more secured and economical solution for multi- line congestion cases.