Electricity distribution Flashcards
What voltage levels are used in the UK electricity distribution system?
400/275kV for transmission (EHV)
What is the purpose of the Electricity Act in the UK?
It regulates electricity distribution licensing
What are the main functions of a distribution network?
- Maintain the network
- Build new connections
- Operate the system
What are the key performance standards for Distribution Network Operators (DNOs)?
- Reconnect supplies after faults
- Correct voltage issues
- Meet guaranteed performance targets
What is the expected annual outage time formula?
u = r * t
where r is the average outage rate and 𝑡 is the average outage duration
How does a radial system with backup improve reliability?
It reduces total outage costs by providing alternative paths for electricity flow
What is the purpose of the Distribution Security Standard (ER P2/8)?
To ensure a minimum redundancy level for different load groups
What are the basic design principles for electricity distribution networks?
- Develop efficient networks
- Reduce losses
- Ensure compliance
- Improve performance
Why is load forecasting important in power systems?
It helps plan future network development, manage faults and schedule maintenance
What is the function of SCADA systems in electricity distribution?
- Monitor and control the network in real time
- Ensure safety
- Manage emergencies
What are the main components of an overhead line?
Conductors, insulators and supporting structures (towers/pylons)
What is the function of transformers in distribution networks?
Change voltage levels, regulate output and provide cooling
What are two main types of switches?
Load-switching switchgear and isolators
What is the primary purpose of network protection systems?
- Minimize damage during faults
- Ensure system stability
- Reduce service interruptions
What are common types of network protection systems?
Overcurrent, distance, unit protection and loss of mains protection
