• Electrical India
  • Feb 5, 2017

The major operating challenge to transformer differential protection is maintaining security during CT saturation for external faults while maintaining sensitivity to detect low magnitude internal faults. CT saturation reduces the secondary output from the CT, and cause a false differential current to appear to relay…

  • Electrical India
  • Feb 5, 2017

Selection of the Circuit Breaker has to be done carefully, so that it does not allow the transformer to exceed the permissible winding temperature. The built-in Bi-metallic strips mounted in the Circuit Breaker, located below the top oil, achieve the temperature sensing function. The circuit breaker thus provides Thermal matching with the transformer & protects it against over loads...

  • Electrical India
  • Oct 5, 2016

Electrical equipment like transformer, generator, CTs, PTs and motor requires to be protected from over voltages. Surge arrester is used to protect these equipments from lightning and switching over voltages. Modern day’s surge arrester uses Metal oxide varistor as an active element and provides exceptional overvoltage protection to the equipment connected to the power system...

  • Electrical India
  • Jul 5, 2015

Transformers are a critical and expensive equipment in the power system network. They function as a node to connect two different voltage levels. Hence, the availability of their service is vital in maintaining the continuous power supply to consumers. Since many decades, differential protection provides the best overall protection for a power transformer to protect against faults...

  • Electrical India
  • Mar 5, 2015

The accuracy and uncertainties of diagnosis with dissolved gas analysis (DGA) is not satisfactory through conventional diagnostic techniques in power transformers. On other hand computer’ applications have found wide spread applications ‘human-like’ capabilities to make judgments, guesses, change of opinions.

  • Electrical India
  • Mar 5, 2015

Different types of Transformers are used in power system. Commonly used power transformer is oil filled power transformer. In the oil filled power transformer oil act both as insulating and cooling media. During an internal fault resulting in an arc will cause fire. The fire may spread resulting from ignition of oil, causing explosion of tank, rupture of tank, core and winding and also burning the neighbouring equipment’s.

  • Electrical India
  • Mar 5, 2015

The Indian economy is growing at a rapid pace and so in Indian power system. The installed capacity of 2.03 GW is planned by the year 2011-12 and the estimated peak demand is expected to grow to 150300 MW in the year 2011-12. With the result, the transmission & distribution is increasing many fold. However, the use of existing infrastructure to their optimal capacity rather than providing additional corridor is essential in order to have economical operation of grid.

  • Electrical India
  • Mar 5, 2015

Current transformer is an important link in power system that helps us to measure, monitor & protect the power system. As such, the correct selection and specification of a current transformer also becomes a very important task. Unfortunately, not much attention is paid to correctly specify the CTs.