Benchmarking of hydroelectric generator compliance for the European network code on requirements for grid connection

The liberalization of the electricity supply has led to the unbundling of the electric utility industry in which vertically integrated utilities have been split into generation, transmission, distribution and retailer companies. Precisely, Transmission System Operators have developed Grid Codes to formalize the technical obligations of the power system players with respect to the transmission grid. Grid codes have been developed mainly at national level (Rouco 2012). The diversity of the grid code requirements in Europe (Van Hulle 2010) have motivated a harmonizing effort lead by the European Network of Transmission System Operators for Electricity (ENTSO-E) by mandate of the European Commission (ENTSO-E 2017). The European Commission have recently approved a network code on requirements for grid connection of generators (European Commission 2016). The European network code on requirements for grid connection of generators provides a framework that has to be implemented at national level. It is now under such implementation phase.
This paper reports an investigation, jointly carried out by Iberdrola and Universidad Pontificia Comillas, on the compliance of the generators of a large hydroelectric plant with the recently approved European network code on requirements for grid connection of generators. Three issues raised by the European network code will be addressed: fault-ride-through capability, active power frequency response and voltage stability.
The paper is organized as follows. Section 1 reviews the requirements of the European network code for grid connection of generators. Section 2 details the case study. Section 3 contains the simulation results. Section 4 provides the conclusions of the paper.