Modelling and methodology apllied to evaluate multi-infeed performance of HVDC transmission systems.

• Autor(a) principal: Pedroso, Felipe Rocha Velloso de Almeida
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: http://www.teses.usp.br/teses/disponiveis/3/3143/tde-27042018-092616/
• topic: Ângulo de extinção; Commutation failure; Compensador síncrono; Extinction angle; Falha; HVDC; LCC; Multi-infeed; Statcom; Synchronous condenser; Transmissão de energia elétrica

The Brazilian transmission system covers a large area, with a high concentration of consumer centres in the Southeast region and abundant hydro generation in the North. To connect these regions, some of the transmission lines might reach 2500 km length, creating a challenging situation. In this context, system planners have been defining the use of HVDC systems as the most feasible choice of transmission investment. It is so, recognized that the connections of power plants in the Northern region to the load centres in the Southeast will require a significant number of bipoles and, until the present moment, all the operational and planned HVDC lines are based on the converter technology known as LCC (Line Commutated Converter) and consequently subject to commutation failure. Currently, the Brazilian system has four LCC bipoles, with two other bipoles under construction. Although the Southeast grid is strong, the connection of two additional bipoles is a concern as the interaction between these inverters may cause strong effects on one another, a phenomenon known as multi-infeed interaction. In such a situation, the assessment of the system operation, possible outages and possible mitigation methods are of paramount importance. This document presents a different methodology for the analysis of the multi-infeed system mentioned and focuses on its validation by analysing operation under normal conditions and with the implementation of established mitigation methods. The investigation was carried out with EMT, power flow, short-circuit and electromechanical softwares in a very large AC system composed by 100 buses on EMT and full Brazilian system on the rest. The effects of faults were analysed and the areas containing the buses where a fault leads to multiple commutation failures were identified.