enercon midterm

• Goals of engineers for electrical power transmission

  • Efficiency
  • Robustness
  • Safety
  • Cost
• Electrical power transmission


  1. Transport electric power over distance with minimal losses

  2. Transport power through urban and rural areas minimizing harm to people and animals

  3. Use the minimal raw materials and building/operating costs possible

  4. Create a system which is not vulnerable to surges and can 'heal' itself when outages occur
• Since the first long distance power transmission to Munich Germany in 1882 humans have made every mistake possible and learned from it
• Engineers are still trying to solve very difficult problems like cost control and resistance to solar flare events which could knock out power worldwide
• Ways to transport electrical power over long distances

  • High Voltage Alternating Current
  • High Voltage Direct Current
  • Superconducting Technology
  • Wireless Power Transmission
• Alternating Current (AC)


  • AC power can be easily converted from low to high voltages and back again
  • AC Power is good for power grids as it distributes itself throughout a grid and can 'heal' by routing power around an outage area
• AC Power is the most common method of power transmission in the world
• Lines are suspended high above the ground as they produce an electromagnetic field around the wire
• The higher the voltage, the larger the electromagnetic field generated around the wire
• Negatives of AC power

  • Significant losses from induction (electromagnetic fields)
  • Needs quite a bit of conductor (3 wires, sometimes more)
  • Lots of complex apparatus required to keep voltages, phases and other aspects under control
• Engineers are constantly improving our AC power transmission system
• High Voltage Direct Current (HVDC) was the first form of long distance transmission in 1882
• HVDC lines are not in a 'grid' configuration which can evenly distribute power, but consist of a single long distance line connecting major grids with 'valves' at each end
• HVDC grids cross China, the US and Europe, connecting major geographic areas
• HVDC is especially useful to connect islands like Great Britain and Japan as it can go under water
• Advantages of HVDC over HVAC

  • Peak Voltage: DC can carry twice the power at steady DC voltages compared to AC peak voltages
  • Radiation and Capacitive Loss: AC power radiates and has capacitive coupling, HVDC doesn't have this problem
  • Skin Effect: AC high voltage often uses clusters of wires, HVDC can have just one large cable which can be cheaper
• The 450-megawatt Mindanao-Visayas Interconnection Project (MVIP) now connects the Mindanao and Visayas grids through a High-Voltage Direct Current submarine cable
• If we use superconductive conductors in super cold temperatures we can deliver power through underground cables with almost no loss at all, but this technology is not yet cost effective
• Wireless power transmission is extremely inefficient going through the medium of air, and it is deadly for animals like birds passing through the high powered beams
• It is unlikely wireless power transmission technology will ever be useful, especially since we are leaping ahead with HVDC, achieving impressive levels of efficiency
• Power transmission in the Philippines

  A common carrier business (i.e. regulated by the government, serves its franchise area without discrimination, responsible for any losses incurred during delivery)
• Power transmission in the Philippines is regulated by the ERC who has rate-making powers and the final say in the valuation of transmission assets
• Pursuant to the Electric Power Industry Reform Act (EPIRA) and the Transmission Development Plan, maintenance and operations of the nationwide transmission system was subjected to competitive public bidding conducted by the Power Sector Assets and Liabilities Management (PSALM)
• Philippine transmission system


  • Luzon Grid
  • Visayas Grid
  • Mindanao Grid
• The Luzon Grid has a network of 500,000 volt transmission lines
• The Luzon Grid is interconnected with the Visayas Grid through the HVDC Leyte-Luzon high voltage direct current transmission line and submarine cable with a transfer capacity of 440 MW
• The Visayas Grid is composed of five small grids (sub-grid) connected with submarine cables, but arranged in a radial configuration, that may disconnect one sub-grid in case a fault develop on one submarine cable interconnection
• The Mindanao Grid is composed of 138,000 volt lines for long-distance transmission, and primarily relies on hydropower
• The National Grid Corporation of the Philippines placed proposals for submarine cable links between Visayas and Mindanao, to unify the three principal grids, and between off-grid Mindoro and Luzon, to increase power reliability in the off-grid island
• Many islands still remain off-grid, relying on localized power plants or power barges for supply
• NGCP


  A privately owned corporation in charge of operating, maintaining, and developing the country's state-owned power grid, an interconnected system that transmits gigawatts of power at thousands of volts from where it is made to where it is needed
• NGCP performs its mandate as transmission service provider with the full awareness of its nature as a public utility
• The National Grid Corporation of the Philippines

  Privately owned corporation in charge of operating, maintaining, and developing the country's state-owned power grid
• While the three main grids encompass each island group, many islands still remain off-grid, relying on localized power plants or power barges for supply
• NGCP


  Performs its mandate as transmission service provider with the full awareness of its nature as a public utility, and in full compliance with the rules and regulations of the regulator, and existing laws governing its transmission operations
• Transmission tower

  • Supports an overhead power line
  • Also called: power transmission towers, power towers, electricity pylons
• Transmission towers

  Carry high-voltage transmission line to transport power from the generating station to electrical substations
• Transmission towers


  • Earth shield wire connected to the tip of the tower's peak
  • Cross arms hold the transmission conductors
  • The size of the cross arms is different for the transmission of various voltages
  • The cage holds the cross arms
  • The shape of the cage may be a square or triangle, depending on the height of the tower
  • The transmission tower body provides the height of the tower required for ground clearance
• Distribution


  The circulation of electricity to end-users is a controlled common carrier business requiring a national franchise
• The power to grant national franchises is exclusively vested to the Congress of the Philippines