Ultracapacitor-BESS-based coordinated voltage frequency control in a hybrid interconnected power system

A coordinated control scheme with frequency and voltage is investigated for a two-area power system that consists of a thermal, dish-stirling thermal plant and a wind turbine generator under a conventional environment. The capacity area ratio is 1:4. To make the system realistic, nonlinear phenomena such as generation rate constraints and governor dead bands along with time delays are also modeled in the proposed system. A popular and tested two-degree-of-freedom proportionalintegral-derivative controller is utilized as both a secondary ALFC controller and an AVR controller in both areas to achieve an area control error of zero. The controller gains and other parameters are tuned by a powerful sine cosine algorithm that adopts the Dingo optimization algorithm. Different studies have been carried out on the system dynamics for changes in terminal voltage in one area and the impact on other areas in terms of frequency, tie-power, and voltage deviation. Further investigations are carried out with proper selection of battery storage, namely, battery energy storage systems and ultracapacitors, in both areas. The optimum location is also checked for both batteries to ensure that the system is suitable for coordinated frequency and voltage control.