ECE 562 - Spring 2020

Project 3 - Due Feb 18

You may use any power flow software you wish. However, if you don't use MATPOWER, then make a note on your project report describing the software that you used (e.g., PTI's PSS/E version xx, attached C code, attached Excel spreadsheet). Use the new secure (no overload) ESCA 64 bus system.

Power Transfer Distribution Factors

  1. Choose either control area 1 or control area 3 to export power. Within the control area of your choice, select any set of generators (at least three) to export power, including the swing if you'd like.
  2. Define "source" proportionality factors for the generators based on the initial Pgen output for the generators you chose above.
  3. Within control area 2, choose any set of PQ load buses (at least three) to import power via increasing load.
  4. Define "sink" proportionality factors for the load buses based on the initial Pload value for the load buses you chose above.
  5. Determine a MW transfer level, based on a PTDF calculation, that overloads at least one branch beyond its Rate A limit (normal/long-term rating). Ignore the Pmax values of the generators for this project.
  6. Estimate the new branch MW loadings via the Power Transfer Distribution Factors (PTDF's).
  7. Calculate the exact branch MVA loadings via Newton-Raphson power flow. Be sure to increase the Pgen, Pload, and Qload values to model the additional MW transfer determined above. *** Make sure that your AC power flow converges. You cannot use power flow results from a non-converged power flow solution.
  8. When increasing the Pload and Qload values to import power via constant power factor at a specific bus, use the same multiplicative factor to scale both P and Q load at the bus:
    Pload_new = Pload_old + factor*Pload_old
    Qload_new = Qload_old + factor*Qload_old
    By using "factor" to scale both the Pload_old and the Qload_old, you will be increasing the load at a constant power factor.
  9. Analyze your results and submit the deliverables below

Deliverables

  1. Brief description of project.
  2. Short description of your simulation: include solution parameters, active control devices, generator sources (bus #, additional MWs), load sinks (bus #, additional MWs and MVARs), total additional MW transfer applied to system.
  3. Table with the top 10 post-transfer most heavily-loaded branches (measured in loading percentage) based on the actual MVA loading determined by power flow. Your table should include the following columns:
    1. Branch data (From, To, MVA rating, pre-transfer MVA loading)
    2. ParFac
    3. Estimated post-transfer MW loading from PTDF calculation
    4. Actual post-transfer MVA loading from power flow (Be sure to use the maximum MVA flow from the two ends of the branch.)
    5. Estimated post-transfer percentage loading from PTDF calculation
    6. Actual post-transfer percentage loading from MVA power flow
    7. Post-transfer percentage loading error: estimate - actual (e.g., 84%est - 87%act = -3% error)
  4. Table with the post-transfer top 10 largest magnitude estimation errors (measured in percentage loading error). Rank them based on the magnitude of the error, but include the sign so that it's clear which percentage loadings were underestimated and which were overestimated. Your table should include the same ten columns as the previous table.
  5. Brief discussion of your results, including answers to the following questions:
    1. Do PTDF-based calculations accurately predict the actual branch loadings? Why or why not?
    2. Are there any significant errors in the PTDF-based estimates of branch loading levels? Where?
    3. What do you think causes the errors, if any?
    4. Does the location of a branch relative to the source generators or sink loads affect the errors? If so, how?
    5. Did you notice anything else?
  6. All students must submit the code (MATLAB, C, Excel spreadsheet, etc.) they used to calculate the post-contingency branch flows as a section within the report. Then, the report file must be submitted via SafeAssignment on Blackboard. Main Campus students also must submit a hardcopy report at the beginning of class.

Updated 5 Feb 2020