Optimal Sizing and Operation Strategies for VSG-based BESS in Ancillary Service Market

Abstract

In response to the growing global power demand and rising environmental awareness the integration of renewable energy (RE) resources into the grid is becoming increasingly common However the output power of RE is unstable as it strongly depends on the weather conditions; this increases the difficulties for the system operator (SO) to maintain the system frequency via the balance between supply and demand Thus given the ever increasing penetration of RE besides the automatic generation control (AGC) of the synchronous generators other immediate resources should be considered to adjust the frequency This thesis proposes an optimal sizing and operation strategy for a battery energy storage system (BESS) participating in the ancillary service (AS) market not only considering the time-of-use (TOU) tariff which is used to reduce the peak load of the system but also integrating a virtual synchronous generator (VSG) to provide an instantaneous frequency regulation service The method proposed in this thesis improves the dual-stage architecture of BESS capacity planning saving considerable computational resources; however the resulting complexity of the optimization problem increases Therefore the Electron Drifting Algorithm (eDA) is adopted to solve the proposed optimization problem The results show that the quality of the solution can be effectively improved in comparison with other algorithms To verify the feasibility of the proposed method this thesis builds the IEEE 30-bus test system and a practical micro-grid for dynamic analysis by using the power system simulation software PowerFactory DIgSILENT Simultaneously realistic photovoltaic (PV) power generation data load profiles and AS data of PJM electricity market in USA are included to assess its cost-effectiveness Moreover this thesis considers not only the point of view of BESS investors and their benefits but also that of the transmission and distribution (T&D) industry in terms of the cost of additional frequency regulation in high RE-penetration system The simulation results show that this thesis provides a business model with sufficient incentives to promote investments in BESS not only yielding economic benefits but also effectively increasing the robustness of the grid and further accommodating the implementation of additional RE

Date of Award	2017 Aug 7
Original language	English
Supervisor	Hong-Tzer Yang (Supervisor)