Avaliação do aumento da capacidade operativa de compensadores síncronos através da excitação negativa e efeitos na estabilidade e proteção de perda de excitação

Abstract

The synchronous compensator is equipment widely used to control the consumption or absorption of reactive energy from the electrical network, which results in the optimization of the system's operational capacity. To increase its operating range, it is possible to operate underexcited in the region of minimum excitation of the machine, through negative excitation. The operation of the synchronous machine in this region places it close to the practical stability limit, where disturbances in the system can compromise the angular stability of the machine. In this context, this work presents computational simulations to evaluate the increase in the operating range of the synchronous machine, exploring the effects on angular stability in conditions of disturbances in the system. Subsequently, the minimum excitation limiter and the protection against loss of excitation are adjusted, in coordination with the limiter, to evaluate the effects on this protection. The results obtained show the possibility of operation in the underexcited region of the machine, in which the underexcitation limiter performs the control action in a coordinated manner with the loss of excitation protection.