Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by QBplanner

  1. QBplanner

    transitory stability

    @Mbrooke No problem, even rudely beg to differ is fine for me. What I imply is for an "existing system", if there is a bus fault causing three elements out, typical utility way nowadays is to save money by either trip generation or load other than re-configure the system like what you proposed...
  2. QBplanner

    transitory stability

    Got it which means you over shed the load.
  3. QBplanner

    transitory stability

    I assume you used absolute angle other than relative angle for each machine. You may want to use relative to the system one. I did not see the 0.7p.u. voltage profiles in the drawing. The voltage profile seems too high at two buses all beyond 1.1pu. Hydro units is easy to shed within cycles...
  4. QBplanner

    transitory stability

    When u get into a N-3 scenario, any capital investment to improve the system is not necessary. Under N-3, only a few things you can do, RAS to trip the units and shed load, system separation to avoid cascading etc. I have not seen any utilities spending money to fix N-3 scenarios.
  5. QBplanner

    transitory stability

    If the generators are Hydro units, then just shed the units until the remaining generations are within synchronism with the rest of eth system. Generation run back can not do much to the rotor angle stability it takes at least 5-10 seconds to act which the machines are already gone. From the...
  6. QBplanner

    transitory stability

    You may try different generation shedding capacity or shedding times at the generation station connecting to S.osorio
  7. QBplanner

    DTT for small distribution generator

    @divadbeach Maybe in the utility you r in that planners only know the positive sequence network. In the utility I am in we calculated SLG impedance by hand using positive, negative and zero sequence network impedances. Also when performing EMTP study, we have much complicated model than P&C...
  8. QBplanner

    Hypothetical question in regards to system design and protection

    Again, you may require a lot of experts when designing a new EHV system. The reason I refer to Hydro Quebec is because it has a strong transmission planning team back then and has IREQ to provide technical supports for any type of issues relate to their 735kV system. I worked there for a few...
  9. QBplanner

    Hypothetical question in regards to system design and protection

    No the Braking effect is during the fault to allow the generator to continue to output the electrical power and have less kinetic energy stored in the machine therefore less accelerating power after the fault is cleared and the generator will not swing beyond certain angle say 90 degree C (just...
  10. QBplanner

    Hi Folks i am trying to simulate

    Which type of simulation tool are you using? if possible you can show the simulation diagrams for both conductors from generator step-up Trx to the receiving end. better with voltage, phase angle and line current/MW/MVar. From the datasheet of the conductors you provided, it does show KIWI...
  11. QBplanner

    Hypothetical question in regards to system design and protection

    "But from everything I am gather thus far is this: If I was to build a new system having many dozens of 500MW generating stations scattered around a dozen load pockets 20 miles away- or really any system with lots of load a generation evenly scattered about- it is absolutely in my best interest...
  12. QBplanner

    Hypothetical question in regards to system design and protection

    A new system design is more complicated depending on lot of factors distances between the loads center and generations, size of the loads and generators, required design criteria, network topology you want to achieve from long term perspectives, type of the generators, types of the loads, how to...
  13. QBplanner

    Hypothetical question in regards to system design and protection

    @HamburgerHelper System planners typically perform the various rotor angle stability studies to define the required fault clearing time and pass the requirement to P&C. If the machine loss of synchronism after faults no matter how fast the fault clearing time can do 4 cycles the fastest one I...
  14. QBplanner

    Hypothetical question in regards to system design and protection

    " increase the critical clearing time " I thought all the system design and P&C schemes is to reduce the critical fault clearing time not to increase it. Am I missing anything?

Part and Inventory Search