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  1. bilalk

    Solar Power Generation

    Hi, I agree, of course for anything beyond coffee chat stage, you may want to conduct some more accurate calculations. On another note, I wonder if the declining performance output of Omegamaneltj's pv system may be attributed to the PID phenomenon in solar panels. PID stands for Potential...
  2. bilalk

    Solar Power Generation

    omegamanltj: I agree with you. It is safe to derate the nameplate capacity with at least 20 to 40% in order to account for location and weather conditions. and yes, it is a ballpark figure, but why not also good enough for I&C applications?
  3. bilalk

    Solar Power Generation

    If accuracy is not an issue, I usually go by the rule of thumb for a quick feel. The key is to go by the total nameplate capacity of the generator and not dive into efficiency calculation of each individual module. Note: the following calculation is valid for northern areas such as Toronto...
  4. bilalk

    Transformers in series

    ProJPS, do you mean that the primaries of both transformers are connected in series (as LOOP FEED for instance) or is the secondary of the first tx serving as input to the primary of the second tx? In general, efficiency is always output as it relates to the input. So in the first case above...
  5. bilalk

    220/11kV Transformer- Minimum Rating?

    My experience with transformer manufacturers is that they can build for you anything you want. However, here are some points I would like to make aware of before issuing your supplier's bid: - figure out the right tx configuration (Y-Y, D-Y, Yg-Yg, D-Yg, and so on) because this will affect the...
  6. bilalk

    Sleeper Project Contract Clause

    I enjoyed reading the responses to this posting. I am dealing with similar issues. In the Distributed Generation business today, project owners, developers, regulators, utilities, engineers, and consultants are all in the flux facilitating the legal contractual aspects of this business. There is...
  7. bilalk

    Ground Grid Resistance of Padmounted Transformers

    The NEC states that the resistance of man-made electrode shall be 25 ohms or less. Most literature out there discuss the ground resistance values in distribution substations to be under 5 ohms or better under 1 ohm. I could not find any document that discuss the ground resistance value of ground...
  8. bilalk

    Power Transmission/Distribution Simulation Software

    I am not sure if that helps so far, but I think EDSA (www.edsa.com) has a powerful package relating to electrical distribution calculations for short circuits, power factor calculations etc....
  9. bilalk

    difference between SVC & shunt capacitor ?

    I wonder who can help me in answering this question that relates to the SVC from Shalhoob: The dynamic var compensators have capacitor banks which are equipped with discharge circuits that requires a maximum of 10minutes discharge time for the capacitor and/or the bank. Are discharge circuits...
  10. bilalk

    difference between SVC & shunt capacitor ?

    Shaloob, you welcome. You can read more on DVC for example at the website of the company www.sandc.com under Power Quality and then AVC (or Adaptive Var Compensators). As Eng. Saleh was saying, the switching of capacitors produces harmonics, which require filters. Therefore, the AVC has a...
  11. bilalk

    difference between SVC & shunt capacitor ?

    hi, I used to work with adoptive var compensators in the past. Capacitor banks are mainly used for Power Quality applications, such as voltage sags, voltage flickers, and power interruptions. Sags are short term reduction in voltage and power interruptions are zero-voltage events. Both can be...

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