Software Patches

September 10, 2021

Bug Fixes

  • Optimal Power Flow (OPF): In very rare situations for Interface definitions that contain many BRANCHOPEN InterfaceElements that result in the complete isolation of parts of the power system the calculation of the interface flow could become inaccurate. This could mess up calculations such as an OPF solution which uses the Interface MW flow to calculate the OPF solution. Internally, a numerical summation of very large values is done and that calculation was incorrectly using single-precision floats (7 significant digits). A user encountered an example where the equivalent of the subtraction of (123456789 - 123456789) was not returning 0.0 but instead what appeared to be random 2 digit number. This has been fixed by using double-precision instead to maintain enough significant digits to prevent this bug.
  • Transient Stability: Fixed the option on the Transient Stability dialog when processing multiple contingencies to choose whether to show results by a single contingency or multiple contingencies on the Results from RAM tabs.