Defining Control Strategies for MicroGrids Islanded Operation

J.A.P. Lopes, C.L. Moreira, A.G. Madureira
2006 IEEE Transactions on Power Systems  
This paper describes and evaluates the feasibility of control strategies to be adopted for the operation of a microgrid when it becomes isolated. Normally, the microgrid operates in interconnected mode with the medium voltage network; however, scheduled or forced isolation can take place. In such conditions, the microgrid must have the ability to operate stably and autonomously. An evaluation of the need of storage devices and load shedding strategies is included in this paper. Index
more » ... ic response, energy storage, frequency control, microgrid, power system dynamic stability, voltage control. I. INTRODUCTION T HE need of reducing emissions in the electricity generation field, recent technological developments in the microgeneration domain, and electricity business restructuring are the main factors responsible for the growing interest in the use of microgeneration [1], [2] . In fact, the connection of small generation units-the microsources (MS), with power ratings less than a few tens of kilowatts-to low voltage (LV) networks potentially increases reliability to final consumers and brings additional benefits for global system operation and planning, namely, regarding investment reduction for future grid reinforcement and expansion. In this context, a MicroGrid (MG) can be defined as an LV network (e.g., a small urban area, a shopping center, or an industrial park) plus its loads and several small modular generation systems connected to it, providing both power and heat to local loads [combined heat and power (CHP)]. The Consortium for Electric Reliability Technology Solutions (CERTS) initiated the research on the impact of connecting large amounts of distributed energy resources (DER) to LV networks in order to enhance the reliability of the electric power system and developed the MG concept [1]. The MG is intended to operate in the following two different operating conditions. • Normal Interconnected Mode-the MG is connected to a main MV network, either being supplied by it or injecting some amount of power into the main system.
doi:10.1109/tpwrs.2006.873018 fatcat:c62dfk2ffjgdznt3sl47vw3cp4