Software Patches

July 24, 2015

Features and Improvements

  • File Formats: For UCTE format, added reading the regulated voltage for tap-changing transformers and regulated MW flow for phase shifting transformer. For tap-changers regulated voltage is read as the value specified +/- 0.01 per unit. For phase-shifting transformers regulated MW flow is read as the value specified +/- 5 MW.
  • Transient Stability: On the Transient Stability Dialog, we were finding that the button on the Result Storage page called "Load from Hard Drive File into RAM results specified by Store to RAM Options" was causing confusion. Users were assuming that in order to plot results or use the Transient Contour Toolbar that results must first be loaded into RAM. This has never been the case as these features simply obtain data directly from the TSR file without requiring you to load results into RAM. The same button is available at the bottom of the "Results from RAMTime Values" and in practice the only place that you see these results from RAM is on this page. To avoid continued user confusion, we have removed the button from the Result Storage tab and it is now only available on the Time Values page.
  • Transient Stability: When loading in transient stability data from an AUX, DYD, or DYR file, Simulator would prompt you asking "Do you want to clear the existing transient stability data first?". Feedback from many users was they would NEVER want to do this and it was a dangerous dialog to continually show users. We have removed this prompt and the clearing of stability data when loading a file.

    If a user still wants to delete all stability models from their case, this can still be done under the AddOns ribbon tab under the drop down Stability Case InfoClear All Transient Stability Data.
  • Transient Stability: In the Transient Stability dialog, modified the drop-down showing all the transient contingencies in the so that the strings also show the categories of the contingency (if any categories have been assigned)

    In the Transient Stability dialog, added a Find button next to the drop-down showing all the transient contingencies. The Find button allows you to find by either
    1. Name of the Transient Contingency
    2. Find the first transient contingency that has a transient contingency element that acts on a generator, load, bus, or switched shunt.
  • Bug Fixes

    • Contingency Analysis: Improved the processing complex contingencies which involve several POSTCHECK iterations to ensure that large generation changes are handled efficiently.
    • File Formats: More changes to reading the Min/Max phase shift values from a UCTE file format to ensure that the Max value is the positive one and the Min value is the negative phase.
    • File Formats: Fixed error in how Generator records were being read from the UN records in an hdbexport file.
    • File Formats: Fixed error in loading in RAW file which contained an VSC DC Line if the remotely regulated bus was not specified.
    • File Formats: When reading in a 2-winding transformer in a RAW file, the cosmetic storage of the Fixed Tap ratio on the to-bus side was not being done properly when the flag CZ=2 and when the nominal kV of the secondary winding was different than the nominal kV of the bus. This has been fixed so that you can see the values on the transformer base correctly inside Simulator. Note, this did not effect the solution as we were still converting and storing everything in Simulator on the System MVA base correctly. This only effecting viewing input data on the transformer base.
    • General: When saving a case it is possible to configure Simulator bring up a dialog asking you to add a comment to the case. It is also possible to configure Simulator to automatically save a case every so many minutes. This was bringing up the case comment form constantly. The Auto-Save feature has been changed to never show the case comment box.
    • Power Flow Solution: Made a change to how the Mvar limits are enforced by switched shunts operating as SVCs.
    • Transient Stability: modified how error messages are reported when we write out a model which can not be found in the case when reading a DYD file so that the error messages work when the DYD file contains labels as well.
    • Transient Stability: For a GENTPF/GENTPJ model when setting Tdopp or Tqopp to 0.0, this indicates that a transient model should be used for the generation model. The model should then be configured such that Xdpp=Xdp and Xqpp=Xqp=Xq to function appropriately. If the model was not setup this way from the start, then Simulator will change the parameter inside the simulation automatically to be treated in this manner. There was a bug however such that this wasn't properly handled which could cause generation to initialize incorrectly. This was occurring at the LITFAL generation in a WECC case. Simulator will now properly handle this without user-intervention.
    • Transient Stability: For GENTPF/GENTPJ models which had Tqop=0 to indicate special handling of a salient pole machine with a single amortisseur winding, we were not performing any validation checks on the magnitude of Xqpp relative to Xdpp. As a result, invalid data such as Xqpp=0 was not being flagged as an error and was not being auto-corrected. We now perform the same check on Xqpp as we do for all other GENTPF/GENTPJ model and thus if the value is very small (Xqpp<0.01*Xdpp, basically zero) then we set Xqpp=Xdpp.