Power System Analysis and Fault Protection Studies for 120 QUU Sites
Client: Queensland Urban Utilities
Technology: SKM PTW (Power Tools for Windows)
Witthoft Engineering undertook an audit of each site to ensure the integrity of the earthing system, that AS3000:2007 requirements regarding clearance around switchboards, access and egress ways were met, and to confirm as-built information required to perform the power system analysis including:
- Energex Connection Details (Pole #, Meter, Connection Type, Transformer Details)
- Circuit Breaker Make / Model / Settings
- Cable Types / Sizes / Lengths / Installation Methods
- Drive Make / Model / kW / FLC
We then performed the power system analysis to identify issues with the operation of the existing equipment with respect to:
- Improperly coordinated protection schemes
- Lack of discrimination in some circuits
- Incorrectly set protective devices
- Improperly designed protection systems
- Excessive fault clearance times resulting in high incident energy levels and risk to operations personnel
- Risk to operations personnel when operating the control panel (Reset/Start/Stop pushbuttons) (where applicable)
- High prospective arcing currents exceeding rating of existing PPE
- Power factor
- Touch Potential
Finally, we provided the client with a report for each site containing:
- All protection device settings and Time Current Curves
- Comparison of the existing protective device settings against new settings.
- Categorisation of major switchboards with relevant labels designed for installation on each switchboard.
- Assessment of existing system to confirm adherence to AS3000:2007.
- Assessment of the new system to confirm adherence to AS3000:2007.
- A summary of findings.