Monday, April 19, 2010

Fundamental / Power System Electrical Books

Fundamental / Power System Electrical Books:

  1. Protective Relaying: Principles and Applications by J. Lewis Blackburn and Thomas J. Domin, 3rd Edition, CRC Press
  • The method of symmetrical components was discovered by Charles L. Fortescue.
  • In Symmetrical components, the sequence quantities i.e. Voltage and Current are LINE to NEUTRAL or LINE TO GROUND (opposed to Power system where L-L Voltages are used).
  • Positive sequence is a-b-c, 120 deg counterclockwise; Negative sequence is a-c-b, 120 deg reversed to positive sequence; Zero sequence is always in phase
  • Phasors always exist as a set of 3 but never alone.
  • Unbalanced 3-Ph quantities are divided into the seque nce component as they are independent components in a balanced system network.
  • Electric power systems are balanced or symme trical from the generators to the point
    of single-phase loading, except in an area of a fault.

Sunday, April 18, 2010

Wireless Wifi Based Battery Charger for Phones

Wireless Wifi Based Battery Charger for Phones:

Imagine wireless charging of mobile batteries. Its amazing to know that we can harness the energy from the WIFI signals to actually charge our phone batteries. Its simply magic for me as I cannot imagine charging of the batteries on the air ... There are various links available which definetly justifies something like charge on the fly is going to be true ... As per the 3rd link, the Airenergy charger will hit the market this summer for $40, but the battery using the Wi-Fi harvesting technology won't be available until soon afterward.

  1. http://www.engadget.com/2010/01/09/airnergy-wifi-power-system-gives-rca-a-reason-to-exist-video/
  2. http://www.pocketpc-live.com/top-stories/wifi-battery-charger-believe-it-or-not.html
  3. http://www.tomsguide.com/us/RCA-Charger-Battery-Wi-Fi-hotspot,news-5547.html

Saturday, April 17, 2010

Links for IEC61850

      Links for IEC61850
    1. http://www.61850.com/ This link is useful if you want to check the validation of the SCD or ICD or CID files.
    2. http://www.tissues.iec61850.com/default.mspx
    3. http://en.wikipedia.org/wiki/IEC_61850 This is the general wiki. But has few very good presentation on IEC61850.
    4. http://siemens.siprotec.de/download_neu/applications/IEC61850/IEC61850_message_status.pdf
      Interrogation of the IEC61850 message status
      Why is it not possible to detect a failure with convention wiring via binary input?
      A loss of signal can also occur on protocol based communication links
      Why does IEC61850 detect an interruption of the transmission path?
      How does one obtain the message status?
    5. http://siemens.siprotec.de/download_neu/applications/IEC61850/design01/Network%20Sketch%20Design%2001.pdf This link describes the network overview in standard IEC61850 station.
    6. http://siemens.siprotec.de/download_neu/applications/IEC61850/design01/Description%20Design%2001.pdf This link explains the limitation on the number of devices to be connected to the network switch, how many rings are possible in a subnet and many other configuration checklist.

    Concepts to know in Network before you work with IEC-61850 protocol

    Concepts to know in Network before you work with IEC-61850 protocol:

    1. Different IP address - Class B, Class A, ...
    2. Different MAC address -
    3. What is multicast mac address?
    4. What is RSTP ? Rapid Spanning Tree Protocol.
    5. Which protocol is used for Client-Server Communication?
    6. What is subnet?How is it decided ?
    7. What is multimode FO cable vs Single mode FO cable?
    8. Which type of cables are to be used for SIE, SEL and GE devices?
    9. XML, HTML, SCL ...
    10. Ethernet TCP/IP
    11. OSI
    12. Network Switches
    13. How they perform?
    14. Client - Server communication
    Will post the brief description later on.