*Article* **Impact Analysis of a Battery Energy Storage System Connected in Parallel to a Wind Farm**

**Nicolau K. L. Dantas 1,\*, Amanda C. M. Souza 1,2, Andrea S. M. Vasconcelos 1,3, Washington de A. S. Junior 1, Guilherme Rissi 4, Celso Dall'Orto 5, Alexandre M. A. Maciel 3, José F. C. Castro 2, Yang Liu <sup>4</sup> and Pedro Rosas <sup>2</sup>**


**Abstract:** Increasing wind generation insertion levels on electrical grids through power converters may cause instabilities in the AC grid due to the intermittent wind nature. Integrating a Battery Electric Energy Storage System (BESS) in wind generation can smooth the power injection at the Common Coupling Point (PCC), contributing to the power system voltage and frequency stability. In this article, it is proposed to analyze the operation of a lithium-ion battery technology based 1 MW/1.29 MWh BESS connected in parallel with wind generation with a capacity of 50.4 MW. The main characteristics investigated are power smoothing and power factor correction. Experimental results show that BESS contributes to smoothing the active power and correcting the power factor of wind generation, improving the quality of electrical energy at the PCC.

**Keywords:** storage system; batteries; power smoothing; power factor correction; wind generation; power converter; stability; electrical power quality
