Distributed ReStart is a NIC (Network Innovation Competition) project led by Scottish Power Energy Networks (SPEN) along with National Grid ESO and TNEI. The National HVDC Centre has been supporting this project by performing Real Time Simulation studies and HIL (Hardware in Loop) studies with protection relays to de-risk the black start field trials using a distribution connected generator. The studies performed by the HVDC Centre have provided key insights to the project team by investigating: raises in voltage at the generator terminal, reactive power changes at the generator terminal and the performance of generator protection for various black start scenarios in Scottish Power’s Distribution network in the Chapel cross region.
In our recent activity for the project, we verified the generator’s over-voltage behaviour (which is paramount in the investigation) using Real-Time EMT studies, mainly because all the generators have AC protections designed to detect and trip for over-voltages, and in the case of convertors, inner DC controls and protections are also relevant and act even faster. In this case the RTDS-HIL protection study confirmed that the generator would be able to maintain connection following the over-voltages expected when black start energising a Distribution network.
The HVDC Centre is performing further Real-Time HIL tests for the innovative black start controller in the upcoming months to complete the final stage of this project at the Centre.