Protection and control systems analysis of industrial plants with synchronous generators during islanded operation

Author(s)

Fernanda Caseño Trindade Arioli

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Elétrica e de Computação
• Defense date: 2009-02-27

Examining board members

Walmir de Freitas Filho; Jose Carlos de Melo Vieira Junior; Geraldo Caixeta Guimarães

• Advisor: Walmir de Freitas Filho

Abstract

Modern industrial systems are very sophisticated installations with a high number of automatic processes and capability of isolated (islanded) operation after contingences by using onsite generators composed mainly by synchronous machines and steam turbines. Such installations, in the presence of generators, are generically called autoproducers. Since many of these autoproducers are connected to electrical power distribution and subtransmission grids, they must respect the technical recommendations imposed by these utilities. As a consequence, the disconnection of these systems from the grid after islanding occurrence is a mandatory procedure. Soon after the islanding detection by the industrial protection system, the industry and the grid must be electrically separated (isolated) by opening the circuit breaker installed at the low voltage side of the interconnection transformer. Thus, after the separation, the utility can carry out the necessary technical procedures to restore the network. From the industrial system perspective, after the separation, it is necessary to take control actions to guarantee that the industrial system continues operating with quality and reliability. Basically, three actions must be taken: (a) change the operation mode of the speed governor and excitation system of the generators; (b) implement the load shedding system and (c) change the settings of the protection system overcurrent relays. In this context, the objective of this master thesis is to investigate these procedures and propose methods for analysis in order to obtain a better understanding of these issues. With this methodologies development, it is expected that new automatic proceedings can be achieved in a more efficient and systematic way. (AU)

• FAPESP's process: 06/04960-5 - Development of automated methodologies for protection and control of industrial systems with synchronous generators during islanded operation
• Grantee: Fernanda Caseño Trindade Arioli
• Support Opportunities: Scholarships in Brazil - Master