Adequacy and Security Evaluation of Distribution Systems With Distributed Generation

Abstract

This paper presents an adequacy and security evaluation of electric power distribution systems with distributed generation. For this accomplishment, bulk power system adequacy and security evaluation concepts are adapted to distribution system applications. The evaluation is supported by a combined discrete-continuous simulation model which emulates the distribution system operation. This model generates a sequence of operation states which are evaluated from a steady-state perspective using AC power flow computations. Frequency and voltage stability are also assessed using dynamic simulation in order to verify the feasibility of islanded operation. Simulation results are presented for the RBTS-BUS2-F1 as well as an actual feeder from the South of Brazil. The results emphasize the need to consider adequacy and security aspects in the distribution system assessments, mainly due to the ongoing integration of distributed energy resources.

Reliability Evaluation of a Distribution Network with Microgrid Based on a Combined Power Generation System

“…Complete island separation and determine DG, BS and EV in the island. Use the Monte Carlo method to simulate power output of wind generations and photovoltaic power in the island [6]. 2.3.…”

“…Most present studies mainly focus on microgrids with only DG. The probabilistic model is used to simulate the output power of photovoltaic and wind power [6,7], which cover the uncertainty and randomness of intermittent DG, but these two papers do not develop a battery model and ignore the possible influence of batteries. An integrated Markov model that incorporates the DG adequacy transition rate, DG mechanical failure, and starting and switching probability is utilized to give accurate results for the DG reliability assessment in [8], but the method is only applicable to a distribution network with intermittent DG.…”

“…This can provide a more accurate model to simulate the output of wind power generation and reduce the deviation of reliability evaluation. Like [6][7][8], the model only takes DG into consideration and it has no storage options.…”

Rotational Load Flow Method for Radial Distribution Systems

“…balanced operation, constant power load) due to, for instance, uncertainties regarding future load profiles and distributed generation productions. This is the case in adequacy evaluations [4,5], where hundreds of thousands of load flow analysis may be executed, while performance indices are estimated by modeling failure/repair cycles of components and load/generation profiles as stochastic processes.…”

“…balanced operation, constant power load) due to, for instance, uncertainties regarding future load profiles and distributed generation productions. This is the case in adequacy evaluations [4,5], where hundreds of thousands of load flow analysis may be executed, while performance indices are estimated by modeling failure/repair cycles of components and load/generation profiles as stochastic processes.Detailed distribution system modeling and analysis is a well established topic, covered in books such as [6]. Simplified/single-phase load flow modeling and analysis dates mostly to the 80's and 90's and can be divided into two groups: the first group comprises Newtonian based methods adjusted to distribution system analysis [7,8] and the second group includes methods based on iterative forward-backward sweep processes [9,10,11,12,13,14].…”