Noviembre 2, 7 28 29 y Medellín Colombia Medellín Colombia VII Simposio Internacional sobre VII 2013 Planning for Operation of MicroGrids Considering Small Hydro Power Plants: Transient Stability Sandra Ximena Carvajal Quintero Member, IEEE Department of Electrical, Elecrtonic and Computer Engineering Universidad Nacional de Colombia Manizales, Caldas Email: sxcarvajalq@unal.edu.co Juan David Mar´ ın Jim´ enez Department of Electrical, Elecrtonic and Computer Engineering Universidad Nacional de Colombia Manizales, Caldas Email: jdmarinj@unal.edu.co Santiago Arango Aramburo Department of Decision and Computer Sciences Universidad Nacional de Colombia Medellin, Antioquia Email: saarango@unal.edu.co Abstract—The operation of the electrical distribution system for MicroGrids has the potential for important benefits for power systems, and can reduce the hazards and problems that may arise from its operation. Each MicroGrid presents different operating conditions, because it is shaped by factors that may vary depending on factors such as technology generation, load characteristics, regulations, market conditions, and geographic, economic and environmental circumstances. In this paper, we propose the implementation of a local system control of Small Hydroelectric Plants considered in the operation planning in the form of a MicroGrid. Intentional load outputs tests were performed with a power system simulation model. The model allows to observing the response of the control system and the transient behavior of the MicroGrid. Simulation results show that the implementation of a MicroGrid, the main system’s vari- ables remain within the ranges recommended by international standards; thus, there is a satisfactory behavior for an isolated operation mode of the transient stability. Index Terms—Frequency control, Hydroelectric power gener- ation, Microgrid, Performance analysis. I. I NTRODUCTION A MicroGrid (μG) is defined as a portion of a distribution system that can operate in parallel with the grid or isolated of it in case of partial or total disconnection from the electric power system. A μG is made up of controllable and not controllable loads as well as distributed energy resources such as Distributed Generation (DG) and Storage Elements [1]. μGs are considered emerging king of operation of the distribution systems that have the ability to offer benefits to the operation of the electric power system and the society in general [2]; However, in order to implement this type of operation in an electrical distribution system, it is necessary to begin a planning process of the μG that basically assesses the status and configuration of the current distribution system to propose and perform the required adjustments of the existing infrastructure [3]. Stability in the electric power systems is primarily, due to the planning and operation criteria used to design a system in which a possible number of contingencies and operating sys- tem conditions are assumed, they are: normal state, alert state, emergency state, extreme emergency state, and restorative state [4]. This same concept extends to the planning and operation of the μGs. However, inertia is much lower in the μGs and it basically depends on the control elements of the generation and the load. The generation control system must be designed and modeled to generate in two operation modes: operating connected to the supply network and operating isolated from the mains supply [4]. When the μG operates connected to the system, it does not represent a major challenge in the generation control since the stability depends on the inertia of the system, particularly of large power generation plants. However, when the μG operates in isolation, the stability inside a μG depends on the rapid response of the generation controllers to load changes and the selected control scheme during the planning of the μG, to keep the voltage and frequency variables in the ranges allowed by the network operator [5]. Therefore, the control scheme of the generation requires special care because authors considered it as the most important criterion in the operation by μG [6], [7]. This paper presents the intentional output tests carried out to verify the transient behavior of the μG and the local control system response in a SHP that is considered in the planning for the operation of the system. The control system consists of a Woodward analogelectronic PID speed controller and an IEEE excitation system Type 1 [8]. Testing was done on a simulation model named “Intermediate” μG in MatLab/Simulink using the toolbox SimPowerSystems. This model allows carrying out dynamic studies of systems through the integration of blocks incorporated into the toolbox, particularly μG operation. The paper is organized as follows: in the second section presents an overview of the μG, in the third section describes the case study, in the fourth section are performed simulations and presents the discussion of results obtained, and finally, in section five, general conclusions are made. II. OVERVIEW OF MICROGRIDS (μG) Smart Grids and μG shares three common objectives: maximize generation of small scale assets through integration of intelligence, while greatly increasing the efficiency of the system, causing a reduction in operating cost. [3].A decade ago, international standards such as IEEE Std 1547™[9], did not recommend the islanded operation to utilities companies