Recent Entries

  • Advantages and Disadvantages of Instrument Transformers:

    Advantages and Disadvantages of Instrument Transformers: The advantages of instrument transformers can be as The normal range voltmeter and ammeter can be used along with these transformers to measure high voltage and currents The rating of low range meter can be fixed irrespective of the val...
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  • Comparison between AC and DC UPS

    What are the main types of UPS? UPSs come in three major varieties, which are also known as topologies: Single-conversion systems In normal operation, these feed incoming utility AC power to IT equipment. If the AC input supply falls out of predefined limits, the UPS utilizes its inverter to dr...
  • Conventional substations

    Conventional substation design encompasses the high-voltage switchgear  with copper cables interfacing the primary and secondary equipment. The substation control room has a number of relays and other devices  for protection, SCADA, metering, and so on. They required more ...
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  • Underground distribution cables range from 6.6 kV to 33 kV

    Underground distribution cables range from 6.6 kV to 33 kV in voltage rating, and XLPE cables that employ crosslinked polyethylene as insulator are generally used. It may be said that the history of XLPE cable is the history of countermeasures against water tree, a process of insulation deteriorat...
  • Efficiency of a transmission line

    Generally, power is generated at generating stations and is then supplied to the various categories of consumers through transmission lines. They act, therefore, as pathways for the flow of power from its source to the consumption points in a power system. A transmission line therefore, has both s...
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  • what is banking of the distribution transformers

      The “banking” of the distribution transformers, that is, parallel connection, or, in other words, interconnection,of the secondary sides of two or more distribution transformers, which are supplied from the same primary feeder, is sometimes practiced in residential and light...
  • Backup protection functions

      Overcurrent-time protection (ANSI 50, 50N, 51, 51N) Backup protection on the transformer is achieved with a two-stage overcurrent protection for the phase currents and 3I0 for the calculated neutral current. This function may be configured for one of the sides or measurement locations of ...
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  • Types of tap changer of a Transformer

      A tap changer is a mechanism in transformers which allows for variable turn ratios to be selected in discrete steps. Transformers with this mechanism obtain this variable turn ratio by connecting to several access points known as taps along either the primary or secondary winding. Tap chan...
  • What happens if we open the secondary of a current transformer?

      Current transformers should never be operated with an open secondary circuit. If the secondary of a CT carrying primary current is open circuited, a high voltage can be developed across the CT terminals. Depending on the characteristics of the particular CT, this voltage may be several hun...
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  • Technical Limits to Power Transfers

      Technical Limits to Power Transfers As a transmission line receives power, resistance inherent in the line conductor material converts some of the electrical energy into thermal energy, thereby increasing the line temperature. Line temperature increases as the current flowing through the ...
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