Modeling and analysis of systems with distributed generation operating under unbalanced conditions

• Grant number: 12/04826-8
• Support Opportunities: Regular Research Grants
• Start date: June 01, 2012
• End date: May 31, 2014
• Field of knowledge: Engineering - Electrical Engineering - Power Systems
• Principal Investigator: Rodrigo Andrade Ramos
• Grantee: Rodrigo Andrade Ramos
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated researchers: Artur Bohnen Piardi ; Edson Luis Geraldi Junior ; Elmer Pablo Tito Cari ; Jhonatan Andrade dos Santos ; Jonas Roberto Pesente ; Liciane Cândida Pataca ; Luís Fernando Costa Alberto ; Moussa Reda Mansour ; Romeu Reginatto ; Tatiane Cristina da Costa Fernandes ; Taylon Gomes Landgraf ; WILSON DA SILVA JÚNIOR

Abstract

The electric energy distribution feeders have always operated as passive networks, merely transmitting the energy from the substation to the loads connected to them. Nevertheless, this paradigm recently started to change with the concept of distributed generation. Especially in Brazil, the utilization of the waste coming from the ethanol production is a promising source of electric energy that can be extracted from cogeneration schemes, most of which will possibly be connected to distribution feeders. On the other hand, concerns over the angle stability of multiple generators connected to the same distribution branch prevent, nowadays, the connection of two or more generators to a single feeder. These concerns were mainly related to the non-existence of adequate tools for the analysis of this kind of stability in distribution systems. Among the factors that justified this non-existence, the most important one is certainly the level of imbalance between phases of the distribution system, which is proportionally much more significant than the one observed in transmission systems. This problem is under analysis by the proponent of this project since 2010, under FAPESP Grant number 2009/17920-0, entitled ``Development of a Complete Framework for Stability Studies in Distribution Systems with the Connection of Synchronous Generators'', and a set of tools has already been developed to allow the computational simulation of the nonlinear response of these systems to perturbations of various natures, as well as the small-signal stability analysis, by eigenvalue calculation of the corresponding linear model or by modal estimation techniques. However, for the success in the application of these tools from a practical viewpoint, it is necessary to keep advancing the mentioned research, with the objective of making the tools developed under its scope more adequate to practical applications in different contexts. Based on this argument, the present research project proposes this continuation through the treatment of practical issues associated to the mentioned tools. More specifically, the project will be focused in obtaining reliable parameters for the developed models, so the tools under consideration can provide precise results, which are compatible with those observed in the actual operation of the distributed generators (it is worth noticing that most of the parameters of these generators is not provided by the manufacturers with precision, due to incomplete documentation or even to the resistance by the manufacturer to reveal details of its products that might be involved in commercial secrecy issues). In the present project, the development of an approach, based on parameter estimation (using sampled data from the response of distributed generators), will be pursued with the objective of obtaining reliable values for the distributed generator parameters to enable the practical application of the tools developed under Grant number 2009/17920-0. Furthermore, problems related to the impact of the measurement noise for estimation will also be treated, both from the viewpoint of obtaining model parameters and characterizing the modal content of the response of the generator. The impacts of the protection and control devices typically found in voltage regulators and power factor controllers (that are responsible for the excitation control in these generators) will also be investigated. It is important to remark that the success of this project might significantly contribute to a better utilization of the electric energy from this important renewable source that is the cogeneration from sugar cane waste. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PIARDI, ARTUR B.; PESENTE, JONAS R.; OTTO, RODRIGO B.; RAMOS, RODRIGO A.; IEEE. Evaluation of Volts/Hertz and Over-excitation Limiters Acting under Unbalanced Load Conditions. 2013 IEEE POWER AND ENERGY SOCIETY GENERAL MEETING (PES), v. N/A, p. 5-pg., 2013-01-01. (12/04826-8)

REGINATTO, ROMEU; RAMOS, RODRIGO A.. On electrical power evaluation in dq coordinates under sinusoidal unbalanced conditions. IET GENERATION TRANSMISSION & DISTRIBUTION, v. 8, n. 5, p. 976-982, MAY 2014. (12/04826-8)