During previous centuries, humanity had relied on fossil fuels to generate the demanded energy. Nowadays, the extensive use of oil, gas and coal for energy production is becoming a major problem which concerns modern society. Global warming and climate change are the biggest challenges the scientific community has faced. The main factor which causes those problems is the high dependence on fossil fuels. Moreover, those resources are naturally limited and will extinct in time. For all those reasons, during the last decades, there is intense research on finding ways to produce the needed energy in a sustainable fashion. Renewable Energy Sources have a minimal impact on the environment compared to traditional energy sources. Those resources can effectively tackle the problems which arise with fossil fuel usage. Among all the Renewable Energy Sources, wind energy is the most promising and becomes one of the mainstream power sources in many countries around the world. This happens because wind energy conversions systems have reached a mature stage for wide-scale integration...

The production and consumption of energy in all walks of life is moving towards a greener and more sustainable mix of energy sources away from the traditional sources of coal and gas. With this shift, more renewable energy is expected to be integrated into the grid replacing conventional synchronous generators. In such conditions, the stability of the grid becomes a major concern due to the lack of inertia with the loss of base load generators. As a result, there is an urgent need to develop flexible solutions like Battery Energy Storage System (BESS) to provide ancillary services. Current research tackles it with a piecemeal approach towards frequency and voltage stability. As a result, different types of controller
topology are currently used to get each electrical parameter within the acceptable tolerance limits The contribution of this paper is to build an integrated controller based on droop control to tackle the two parameters of voltage and frequency stability simultaneously with one controller in a holistic fashion. To achieve this goal of demonstrating integrated control, different control schemes were tested and compared in terms of performance with respect to frequency control. The application of the above mentioned integrated control in a decentralized controller environment like a virtual power plant (VPP) was also demonstrated. The testing and design of the control schemes and BESS was done via benchmark models built for real time digital simulation (RTDS). The results show that the control schemes employed in the BESS can effectively contribute towards providing ancillary services in a holistic manner.