Underfrequency refers to a condition where the frequency of the AC supply drops to a value that is lower than its defined value such as 50 Hz or 60 Hz.  Underfrequency is usually caused by overloading a power source or problems with a prime mover such as engines or turbines.

The following are some of the effects of underfrequency

  • High flux density in electric machinery, thereby causing higher magnetizing currents.
  • High core loss and over-heating of the machines and possible failure.
  • Lower efficiency
  • Reduction in speed
  • The fault level increases due to reduced reactance

      Underfrequency situations can be avoided by the installation of underfrequency relays which isolate systems and machinery in the event of an underfrequency.

      Sharp Corporation has signed an agreement with NED(2) to establish one of the world's largest(1) solar power generation plants with a power generation capacity of 73 MW, and to supply thin-film solar cell modules and surrounding systems for the plant. The construction of the solar power generation plant will start in July 2010 and the operation is planned to start by the end of 2011. NED is an independent power producer (IPP(3)) in the Kingdom of Thailand, with a 33.3% stake owned by DGA, a wholly owned subsidiary company of Mitsubishi Corporation. Together with ITD/ITE(4), the largest construction companies in Thailand, Sharp Corporation has signed an agreement for this project.

      The Kingdom of Thailand is renowned for its abundant solar radiation throughout the year. The government of Thailand targets an increase in the amount of renewable energy, up to 20%(5) of the total electricity demand by 2022. The use of solar power generation is expected to grow in the future.

      Thin-film solar cells are optimal for use in a high-temperature climate, compared to crystalline solar cells. Sharp's experience in the mass production of thin-film solar cells has enabled Sharp to take part in this project. The thin-film solar cell modules to be used in the power generation plant will be supplied partially from Sharp's solar cell plant at GREEN FRONT SAKAI in Sakai City, Osaka Prefecture, Japan, which started operation in March 2010.

      Sharp will collaborate with ITD/ITE on the design and construction of the plant. Sharp will take a step forward by not only supplying solar cell modules, but also by offering a business model that provides everything from related equipment procurement to system design and construction of the power generation plant, by collaborating with local companies both domestic and abroad.
      source: pressreleasenetwork.com