Integration of Aggregated Multi-Function BESS to Support Multiple Ancillary Services with a Novel Coordination Strategy

Abstract

In this work, the design and implementation of a dynamic system that integrates aggregated Battery Energy Storage Systems (BESS) into a transmission-level power grid is presented, enabling the provision of multiple ancillary services. The system comprises a dynamic model of BESS, a DC-DC bidirectional buck-boost converter, a three-phase voltage source converter, and a detailed dynamic model of the IEEE 9-bus test system with an integrated 100 MW wind farm. Components are systematically designed then several control loops are implemented to provide multiple ancillary services: frequency response, voltage support, and wind power smoothing. The frequency response control loop ensures rapid active power injection or absorption in response to grid frequency deviations. The voltage support control loop effectively regulates the voltage at the point of common coupling by dynamically adjusting the BESS reactive power output. Additionally, the wind power smoothing control loop mitigates the intermittency of wind power generation. Moreover, A novel aspect of this work is the coordination strategy based on a dynamic PQ chart for the grid-side inverter, which coordinates voltage and frequency outer regulation loops and optimizes the active and reactive power support provided by the BESS, ensuring effective management considering the inverter power limits and BESS constraints and state of charge (SoC). Each controller successfully provides its associated ancillary service, and the coordination strategy ensures optimal utilization of BESS to support all proposed ancillary services simultaneously. The system functionality and its capability to provide the required support are validated through MATLAB simulations.

Date of Award	20 Jul 2024
Original language	American English
Supervisor	KHALIFA ALHOSANI (Supervisor)