1. Voltage Demonstration Steven Gough Innovation and Low Carbon Network Engineer sgough@westernpower.co.uk 0117 933 2170 07810 054850

2. Introduction Background Aims Progress in Phase 1 Phase 1 output graphs Plans for Phase 2 Learning so far

3. Background D-SVC - Static VAr Compensator for Distribution Networks Supplied by Hitachi Can produce 400kVAr leading or lagging 11kV connected via a dedicated 11kV/415V transformer Designed for use on long rural feeders that have Distributed Generation (DG) for voltage control

4. Aims Stabilise voltage for a windfarm at the end of a 11kV feeder Establish the impact of the D-SVC on the 11kV network Test the three different modes available on the D- SVC – Voltage Regulation – Voltage Averaging – Short Term Fluctuations

5. Progress in Phase 1 D-SVC is installed on site adjacent to a 1.5MW windfarm in Cornwall Protection was installed on the LV side of the transformer as there was not a metering unit Monitoring equipment was installed along the feeder D-SVC has been running on various modes for nearly 4 months D-SVC G Summerheath Roskrow WF Kernick Industrial Estate Bickland Hill Primary

6. Phase 1 Output Graphs (1)

7. Phase 1 Output Graphs (2)

8. Phase 1 Output Graphs (3)

9. Plans for Phase 2 Three D-SVCs will be used across two adjacent primary substations A D-VQC (Voltage and Reactive Power (Q) Control System) will be used at the primary to control all three D-SVCs and the tap changer at one of the primary substations Although the site has not been confirmed, there is a combinations of medium wind generation, very long rural feeders and a large number of domestic properties with PV D-SVC G

10. Learning so far When setting up a protection of the D-SVC the protection needs to be on the HV side of the transformer When sizing the transformer for a D-SVC it is important select well above the power requirement of the device The D-SVC can help smooth the voltage The D-SVC can help reduce the range of voltages see on the 11kV

11. Any Questions? Steven Gough Innovation and Low Carbon Network Engineer sgough@westernpower.co.uk 0117 933 2170 07810 054850