Analysis of the Grid Code Fault Ride-Through Requirements for Conventional Power Plants

This paper presents an analysis of the fault ride-through requirements established in grid codes around the world, that conventional power plants should comply, in order to be able to be connected to the transmission network. It describes the causes of this requirement, the way it is currently applied in most electric utilities, and the effect that power plant auxiliaries have in the assessment of this important characteristic. It was found that auxiliaries have a very important effect in the fault ride-through capability of the power plant, and should therefore be explicitly represented in those cases. In addition, it was observed that, in the way this requirement is currently verified, it can be contradictory to stability criteria, and this requires improving the methods of verifying the fault ride-through capability of the plant, so as to conciliate this aspect with stability criteria.