Transient angular stability on medium voltage distribution systems with distributed generation

Abstract

The dynamic behaviour of a 32 MW gas-turbine generating unit, connected to the 23 kV main busbar of a substation, is analysed in this article. The study is focused on the representative faults occurring in an electrical system and allows the determination of the maximum times in with a fault must be delivered to maintain the stability of generator. A three-phase power network is modelled with the Alternative Transients Program (ATP). Simulation results are reported and analysed for typical variables of interest such as machine rotor angle, frequency, and power. According to the study results, machine stability is greatly affected by three-phase faults, as compared to the dynamic behaviour under single-phase faults. The analysis carried out is useful to improve and maintain the security of operation of the electrical grid and in aligned to the current regulations and recent reforms of the Mexican electric sector. The fact that the performed study was usually not mandatory but has been pending since the commissioning of distributed generation plants in the Central Mexican Region is emphasized.