Recent Entries

  • Static Transfer Switch

        Static Transfer Switch consists of two bidirectional thyristor switches equipped with control and protection system. The SSN (1-phase 2-poles) switch has an additional neutral line switch. Control system is based on the fail-safe CMOS logic. Input source and out-put line are protec...
  • Typical protective settings for motors

    Motor protection is used to prevent damage to the electrical motor, such as internal faults in the motor. Also external conditions when connecting to the power grid or during use have to be detected and abnormal conditions must  be prevented. Additionally, the protection relay prevents the di...
  • Earth fault on MV and HV network

        LV earth fault means very small hv overcurrent Earth fault level tends to remain constant   Generally, MV systems are impedance earthed at its neutral end, which limits the earth fault current to around 300 A. Figure  shows the current distribution for an MV earth faul...
  • solar elevation triangles for PV System

    We need to know a few things first:   Module width (assuming landscape mounting orientation): 40 inches for this example.   Module tilt angle: we will use 30 degrees for this example.   Time of day and year we wish to have no shading: we will use 9 a.m.–3 p.m. ...
  • Advantages of Underground Cables vs Overhead Lines

      Advantages of Underground Cables vs Overhead Lines   There are a number of advantages associated with undergrounding of the transmission line across the development which include the following: Reduced visual impact by removing tower No. 11 in the centre of the development and th...
  • Protection Against Fire Substation

        with fire associated with power transformers or oil-filled reactors, where the consequences can be particularly serious and extensive because of the large volume of oil that can catch fire and spread widely (Fig). For more details on protection against fire   ...
  • Buchholz relay

      The Buchholz relay is a gas operated relay used for the protection of oil immersed transformers against all the types of internal faults. It is named after its inventor, Buchholz. The slow developing faults called incipient faults in the transformer tank below oil level operate Buchholz re...
  • Coordination Procedure

        Step 1 – The Generator Owner determines the proper undervoltage trip set point for his machine. This should be based on the manufacturer’s recommendation or protection application circumstances for the generating station. Step 2 – The Transmission Owner...
  • Electrical Network schemes

      Single radial network This is the simplest, least costly network scheme and the one with least overall reliability. The single radial scheme for a net-work with several voltage levels has a tree structure, possibly with backbones which supply the loads distributed along the route.   ...
  • Power Fuses

    Power fuses, shown in Figure  in a typical transformer protective application, provide protection that is both reliable and economical. They are inexpensive—both in   The operating procedure for power fuses is straightforward. Typically, after a fuse has operated, the load-side c...