RESUMO
Abstract With the insertion of distributed generation in distribution networks, security analysis becomes crucial, in islanded operation or when the system is connected to the grid. Dynamic stability analyses are necessary in order to achieve minimum levels of security and reliability. Such analyses are obtained through the solution of the algebraic-differential set of equations that model the distribution grid and their generators, which requires numerical solution methods. Therefore, this paper presents a computational tool for transient stability and large disturbance frequency stability analysis, considering distribution systems with the insertion of biomass-fed distributed generation, which may, or may not, have speed regulation systems. The presented tool may be employed to assess assorted system indexes, such as the severity of disturbances, the quality of a given operating condition, in terms of voltage and frequency operating limits, and the response of both the system and the generators in face of the action of speed regulators.