Technology of VAr Compensators for Induction Generator Applications in Wind Energy Conversion Systems

Many of today utility interconnected wind farms use induction generator (IG) to convert the captured wind mechanical power into electricity. Induction generator has some advantages over the synchronous generator (SG). The main advantages are its robustness and its capability to be synchronized directly to the grid. The main disadvantage, however, is its dependency on the grid for supplying its own reactive power ‘VAr’. Whether fixed or adjustable VAr systems are connected across its terminal, IG must operate at unity power factor at the rated loading while the wind power varies. With supervised control and appropriate coordination, VAr can be used to the benefits of both the wind farm developer and the hosting utility. The incorporation of today adjustable reactive power compensators such as the Static VAr Compensation (SVC) and Static Synchronous Compensator (STATCOM) with IG are vital ingredient toward a successful penetration of wind energy in today distribution grid to ensure voltage stability during the steady state and transient periods.