Error in OneLiner bus fault current report

We just discovered that the total fault current reported by ASPEN for bus faults and close-in faults can be wrong when all three of the following conditions are met:

1. The faulted bus has an active Voltage Controlled Current Source (VCCS), a type-3 wind generator (GenW3), or a Converter-interfaced resource (CIR).

2. One or more of the following fault-simulation options are turned on: VCCS, GenW3, and CIR.

3. The VCCS, GenW3, or CIR unit on the bus did not shut down due to low voltage when the fault was applied.

The screen capture below shows an example of a report with wrong bus currents that are circled in red. The correct result for the same bus is shown on the bottom and is circled in green.

This error may affect the simulation of relay operations within relay groups that are on branches that connect directly to a bus that has an active VCCS, GenW3, or CIR when a close-in fault is applied in front of the relay group.

Additionally, this error may affect the ASPEN Breaker Rating report for breakers on a bus with an active VCCS, GenW3, or CIR when the breakers are set to protect the bus or the branches that are connected to the bus.

This mistake does not affect any other currents and voltages in fault simulation results that the program shows on the one-line diagram and prints to text reports. 

We have fixed this calculation error in OneLiner v15.4 Build 18253 or later.  (The program build number is displayed in the OneLiner Help | About dialog box). Concerned users should write to ASPEN support (support@aspeninc.com) to request a program update with the bug fix.

You can use OneLiner's Bus Fault Summary command to determine the magnitude of the error – if any -- in your OneLiner network, as follows:

1. Before updating your OneLiner to the new version with the bug fix: Run the Bus Fault Summary command to save a baseline report of fault currents at all buses in the network.

2. After updating your OneLiner to the new version with the bug fix: Run the Bus Fault Summary command again to create a report of fault current deviation, which will tell you if any of the buses in the network are affected by this error. Use a low deviation threshold value, such as 0.01%, to get the most accurate report.