Evaluation of methodologies and procedures for the testing of protection system models

Abstract

Protection systems are fundamental for the safety, reliability, quality and maintenance of the electric power supply through the electrical power systems, besides providing safety to the equipment that compose it and the population. However, such protection systems must be designed to operate correctly when necessary and do not act inappropriately, in particular, for transmission line and substation bus protections, responsible for transporting large blocks of energy from generation centers to the loading centers. In addition to causing severe consequences for the operation of the electric system and for the good supply of electric energy to the population, transmission companies suffer large financial losses through the application of Variable Portion Due to Unavailability (PVI) for cases of improper performance. Therefore, it's necessary to carry out model tests for the evaluation and validation of parameterized adjustments in protective equipment before being installed in the field. These tests can be performed through two methodologies: the Open Circuit Simulation and the Closed Circuit Simulation, the first being performed using time domain simulation software such as ATP or PSCAD, together with test boxes, and the second with real time simulators, such as RTDS®. The realization of the last tests entails a financial cost to the transmitting company, however, as already explained, they can prevent an improper performance of the protection system, avoiding financial losses. Thus, in this research we will evaluate the real need of the realizations of these closed-loop tests and the methodologies used in the literature, seeking the advantages and disadvantages of each one to conclude the best cost and benefit for the transmitting company. (AU)