Protective Relay with Fault Ride-through Requirement: Assessment by Closed-loop Test in Real Time

As Distributed Generation (DG) is increasingly integrated into the networks, intermittency issues of some types of DG (such as wind energy) will potentially increase network operating costs or decrease network security. Concern regarding these effects has grown among Network Operators and in order to avoid them, new or updated wind parks are required to provide ancillary services to the network. These ancillary services include the fault ride-through capability and mainly those wind parks connected to a collector switching or distribution substation are asked to provide this service. Although some wind parks can already supply fault ride-through capability to the network, most of them are still largely unable to do so due to the current DG protection scheme. This work concentrates on the development and assessment of new settings for the wind park protection scheme by closed-loop test in real time. This aims to allow wind parks to provide fault ride-through capability to the distribution network. A distribution network with a DFIG based wind turbine with ride-through-fault capability was modelled on the RTDS Simulator. The protective relay settings were then implemented into a commercial numerical programmable relay to be assessed by closed-loop real time test. Conclusions of the protective relay with the fault ride-through requirement are presented and discussed.