Where applicable, you need to share information on the items listed below. For access to the technical specifications from NGET’s extranet website, please contact [email protected]
SSR and Torsional Interaction Analysis
SSR and SSTI (sub synchronous torsional interaction) is to study if the new connections (for example HVDC, windfarms or power electronics-based devices) could inversely impact existing generators or not. The studies check if they can oscillate (or initiate oscillation) with the existing generators or not.
Harmonic Performance Assessment
This is how we make sure that the impact of a new connection on the levels of harmonic voltage distortion on the system are managed to within the limits set in EREC G5 as mandated by Grid Code. NGET performs a harmonic assessment and issues your harmonic specifications of harmonic limits that apply at the point of connection. These may be included in your offer. You then carry out a harmonic assessment and submit a compliance report to demonstrate the compliance against limits or mitigation options if the connection is not compliant.
Electromagnetic Transient Assessment
This is to minimise the probability and severity of electromagnetic voltage transients or transformer inrush at the grid entry point which may occur when your plant and apparatus is connected to or disconnected from the National Electricity Transmission System.
You need to provide NGESO with details of such measures and an assessment of the predicted probability and severity of such transients or transformer inrush. Following submission of this data further information may be required, see PC.A.6.2.1 or PC.A.6.5 of the Grid Code.
Protection and Control Facilities
To provide details of the Protection & Control facilities in line with the Appendix F requirements. The equipment within NGET’s busbar protection or connections protection zone must meet the requirements of the Relevant Electrical Standards. You must:
- Complete and sign the Appendix F, Schedule 1 detailing protection at the NGET/User boundary.
- Provide details of the Circuit Breaker Fail system for review and agreement by NGET.
- Provide details of the CTs and other equipment which connects to and forms part of NGET’s busbar protection system.
- Provide plant indications, GIS gas alarms and busbar protection/CBF alarms to NGET’s Substation Control System for the User bay.
- Your backup protection settings must be submitted to NGET for review and acceptance.
Safety and Operational Interlocking Arrangement
This is required to ensure there is no paralleling of The National Electricity Transmission System through the Storage User’s System. Electrical and mechanical interlocking to be provided by the Storage User in accordance with Technical Specification: 3.01.01_RES.