1. Fault Level Monitor Ken Lennon LCNF Conference 25 th October 2012

2. Process of product development and the need for fault level visibility Basic principles behind the Fault Level Monitor (FLM) Fault level monitor trial results Scope of Presentation

3. Evolutionary change in system generation and load (Smart Grids - LCN). DNO’s have a duty to manage network fault levels, system stability and power quality. Becoming more difficult to programme computer models accurately to predict fault levels. SPEN’s proactive approach to the issue Identified fault level monitor requirements Approached Outram Research Ltd & Led development of FLM product Provided data, computer model analysis for product development and feedback Help pioneer the product and completed field evaluation So why is there a need for measured fault level visibility?

4. Basic principles

5. Upstream Events E.g. Transformer Tap Changer taps down Voltage & Current Dips at the FLM position FLM measures Motor Response and calculates down stream Motor Contribution Downstream Events E.g. Downstream Load changes Current Rises and the Voltage Dips FLM measures Source Response and calculates Upstream Source Impedance Basic principles

6. 90mS RMS 10mS Pk Basic principles

7. Two FLM’s were installed at a Primary substation. The substation feeds a 6.3kV customer via two 6.3kV feeder cables. FLM’s were installed at the metering position as shown in the photograph. The fault level results obtained were very promising. Real World Trial Results

8. Customer Feeder 1 Customer Feeder 2 12.9kA 25.6kA 26.7kA 13.2kA *Model Result 10mS Peak = 26.1 kA *Model Result 90mS RMS = 12.9 kA Real World Trial Results