Reactive power reserve performance control with respect to the transmission grid security

Electric systems and the associated infrastructures (communications and information technology networks, etc.) interfere more and more one another and the global vulnerability increases. Due to the complexity and connectivity, a single infrastructure failure could provoke cascading effects. The transmission system operators guarantee the electric power systems operational security. To manage it as well as possible, system operators use as instruments the ancillary services from generation, supplementary functions performed by the generation units as a support for their basic services. In the nowadays deregulation context, new independent power producers demand the connection to the transmission grid. These new producers are constrained to participate to ancillary services. In order to maintain the operations reliability and to guarantee the grid security, system operators are responsible of the ancillary services existence in appropriate quantities and of the power producers control in terms of ancillary services participation ratio