Protection system impacts evaluation on voltage stability of electricity distribution networks in the presence of distributed generators

• Grant number: 05/03043-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2006
• End date: September 30, 2007
• Field of knowledge: Engineering - Electrical Engineering
• Principal Investigator: André Luiz Morelato França
• Grantee: José Carlos de Melo Vieira Júnior
• Host Institution: Faculdade de Engenharia Elétrica e de Computação (FEEC). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The increasing number of medium and small distributed generators connected in subtransmission and distribution networks is a remarkable characteristic of most electrical systems worldwide. The advantages of this type of generation are followed by the necessity of performing detailed studies to evaluate the generators’ impacts on the stability of power systems. In this context, the distribution systems deserve special attention, because they were originally projected for radial operation, and the utility substation was the only source of power to the loads. In most of the technical papers, books and reports that evaluated the distributed generation impacts on the distribution networks stability, usually, the protection system at the point of common coupling between generator and utility is neglected. In networks with high penetration level of distributed generators, an eventual undesired operation of these generators’ protection systems may cause a voltage collapse, due to the deficit of reactive power. On the other hand, if such protection systems do not properly operate when necessary, a voltage collapse can also occur. Thus, this project proposes the development of a methodology to analyze the influences of the protection systems installed at the point of common coupling of distributed generators on the voltage stability of distribution systems. The analysis will be performed through dynamical simulations considering different technologies of distributed generators, different types of protection devices and disturbances. (AU)