Flexible Distributed Generation. FDG-F Burwell (EPN) May 2017

Transcription

1 Flexible Distributed Generation FDG-F Burwell (EPN) May 2017

2 Principles of Flexible Distributed Generation A Flexible DG connection is a technical and commercial agreement where a generator is allowed to connect an amount of capacity above the unconstrained connection limits. When a network operation threshold is breached, UK Power Networks manages the generator output to ensure network voltages and currents are kept within operational limits. This is operated by an Active Network Management (ANM) solution; FDG-F will be open on the basis of Last-In, First-Out (LIFO) principle where each generator is assigned a position within a global priority stack. When new generators apply for a connection in the area, they are given a position at the bottom of the priority stack and which will be curtailed first during a constraint event. 2

3 FDG-F Flexible Distributed Generation Zone The FDG Burwell zone is defined by the extent of the electrical network within the following geographical area: FDG Burwell Area 3

4 FDG-F Flexible Distributed Generation Zone UK Power Networks Grid Substations within FDG-F are supplied from Burwell Grid Supply Point (400/132kV) and include: Fulbourn Grid (132/33kV and 132/11kV) Burwell Local Grid (132/33kV) Histon Grid (132/33kV) Arbury Grid (132/33kV) 22 Primary Substations (33/11kV) Boundary of FDG-F area is defined by the 11kV network Diagram from Nov 2016 Long Term Development Statement 4

5 FDG-F Installed Generation Capacity A total of 594MW of generation (over 1MW) is included in UK Power Networks assessment, of which 104.9MW are in delivery; 31MVA 41MVA 10MVA 105MVA 263MVA 226MVA Connected Total Accepted Total In Delivery 512MVA CHP PV WIND BIO 5

6 FDG-F Existing Global Network Constraints UK Power Networks continue to work with National Grid in managing potential network constraints at the interface with the transmission system via Statement of Works; The following Global network constraints have been identified in the Burwell area that will be managed by the ANM scheme: Burwell 400/132kV constraints: N-2 security requirement as set out by National Electricity Transmission System Security and Quality of Supply Standards (NETS SQSS) Equipped with 3x Super Grid Transformer with an allowable reverse power flow of 216MVA for N-2; Expected minimum load 26MW. 105MW DG in delivery with an additional 150MW small scale DG forecasted; 240MW DG connection subject to the installation of a 4 th SGT. Further connections. 6

7 FDG-F Existing Global Network Constraints Global network constraints (Continuation) Burwell 132kV constraints: 132kV overhead clearance issues identified. Mitigation in place and design underway to reinforce this section of the network; Rating of 132kV underground circuit cable between Burwell Main Grid and Burwell Local Grid for generators exceeding 35MVA; Burwell 33kV constraints: Transformer reverse power flow protection limitation. UKPN are assessing the use of load blind relays to resolve this constraint; 33kV summer circuit thermal rating reached due to connected generators on the Burwell Local Grid to Linton Primary circuit; Fault level constraint previously identified has been resolved. 7

8 FDG-F Existing Global Network Constraints Global network constraints (Continuation) Fulbourn Grid 33kV constraints: Transformer reverse power flow protection limitation. UKPN are assessing the use of load blind relays to resolve this constraint; Fault level at exceeding the rating of 33kV switchgear. Mitigation in place and reinforcement works planned; Histon Grid 33kV constraints Transformer reverse power flow protection limitation. There are plans to alleviate via the transfer of Histon Primary from Arbury Grid. UKPN are assessing the use of load blind relays to resolve this constraint; 33kV circuit thermal rating. Existing constrained generation export limited to seasonal cable ratings. 8

9 FDG-F Existing Global Network Constraints Local network constraints may be identified in Burwell FDG area as part of the technical assessment which will be managed by the ANM scheme. 9

10 Useful Contacts and Links UK Power Networks will invite customers to apply for a feasibility study for a FDG connection. More information will follow. Useful Links: UK Power Networks DG webpages UK Power Networks Flexible Distributed Generation UK Power Networks Online DG Mapping Tool ENA Active Network Management Good Practice Guide FDG High Level Process FDG curtailment heat maps For further details please contact: DG-Q&A@ukpowernetworks.co.uk 10