Compensation of Current Harmonics by means of Multiple Generation System with Doubly-Fed Induction Generators

The paper presents the topology of a system of power generation connected to a grid based on two doubly-fed induction generators (DFIG) with selective current harmonic compensation capabilities. The scheme uses a grid-side converter supplying DC voltage with two rotor-side converters. A grid-side converter is linked to the network as well as each of the rotor-side converters are associated to the respective generator rotor. DFIG's basic control algorithm aims primarily to obtain maximum power output of wind at variable wind speeds. The possibility of improving the electric energy quality within the power of the converter is realized by compensating the grid current harmonics. The control purpose of the rotor-side converter is to generate a maximum of active power and improve quality of power. The harmonic components of the current are distributed for compensation by two generators separately. To demonstrate the usefulness of the scheme the whole generation system is simulated. The results of simulation are presented.