DYNAMIC STABILITY ENHANCEMENT OF A PLANNED WIND FARM WITH A STATIC VAR COMPENSATOR
John Ch. Dermentzoglou – Demetrios P. Papadopoulos
In the present paper the use of a static var compensator for the purpose of improving the dynamic characteristics of a planned wind farm is investigated.
First, an eigenvalue analysis is performed by taking into account various pairs of gain and time constants of the voltage regulator of the static var
compensator in order to choose the most suitable ones according to the location of the eigenavalues of the system under investigation. Then a further
improvement of the dynamic characteristics of the wind farm is attempted by designing a fixed-gain PID controller with a two stage lead-lag compensator that
uses, as feedback signal, the speed of one of the nine induction generators (IGs) of the involved wind farm and utilizes it as an additional signal to the
voltage regulator of the static var compensator. The validation of the effectiveness of the proposed PID controller is assessed through digital
simulations by using the EMTP-ATP program when applying a 3-phase fault. The controller is also applied to other known operating conditions of the system
through digital simulations to amply verify its suitability.
Keywords: dynamic stability, induction generators (IG's), wind farm, submarine cable, static var compensators, EMTP-ATP program