Describe the electric transmission network or grid.

Description should include

• a definition of transmission―the movement of electricity over long distances via high voltage transmission lines (69-765 kv) from a power station to substations
• identification of basic symbols
• components of the transmission network or grid, such as 
  • power station
  • step-up transformers
  • switchyard
  • towers
  • lines (overhead and underground)
  • transmission substation
  • step-down transformers
  • breakers/fuses. 

Process/Skill Questions:

• What is the role of each component in the transmission of electricity?
• What is the importance of step-up and step-down transformers in a grid/network?
• What are the pros and cons of overhead lines and underground lines?
• Why is transmission only in AC?