LVRT CONTROL FOR WIND GENERATORS IN TERMS OF TWO BESS TOPOLOGICAL STRUCTURES

With the development of battery storage device and technology , many scholars begin to conduct research into the filed and gain considerable achievements. Up to now , two main Battery Energy Storage System (BESS) topologies have been applied to enhance the Doubly-Fed Induction Generator (DFIG) Low Voltage Ride Through (LVRT) capacity. In the first one, BESS units are installed at the DFIG back-to-back converter dc-link. While in the second one , single BESS unit is placed at the point of common coupling (PCC). As the different BESS configurations will result in different working principles and battery demands capacity during the whole process of LVRT. Therefore ， based on the two topological structures ，this paper has made a successful analysis and comparison of output power and battery demands capacity of BESS in the same request of LVRT capacity .