Change Log

2026.7

August 17, 2026

Kestrel EMT

  • Added Multi-Case Runner - New (VERY preliminary) feature! Configure multiple cases and execute them in parallel. This is useful for model quality assessments, model validation, and design evaluations as part of generation interconnection studies (e.g. IEEE Std 2800.2 and PRC-029-1). This feature preliminary, and will change significantly in subsequent releases. Read the Multi-Case Runner section in the Kestrel EMT documentation to understand its limitations.

  • Improved Steady State engine to include an approximation for DC sources.

  • Fixed bug that prevented HDF5 file output for very large timesteps.

  • Fixed localization issue that prevented simulations from running on machines that use the comma separator for decimals.

  • Updated the EPRI IEEE/CIGRE DLL inverter model test case pv_ibr.kcf to implement some basic Multi-Case tests

  • Added back to back capacitor switching example case, cap_sw.kcf

KPlot

  • Added Scaling feature for Siemens PTI PSS/E .out files for the FREQ, VARS, and POWR quantities. You may now specify a MVA base and system frequency and those quantities will be scaled automatically.

  • Added support for “timestamp_epoch” as a valid x-axis column name for plotting CSV files. This is to support KGRID waveform/phasor data exports.

  • Removed origin (0,0) point from CSVs, this improves the plotting experience when the first point of the x-axis data isn’t 0.

  • Invalid numerical data in CSV files is now ignored instead of causing the plot to fail.

2026.5

June 2, 2026

Kestrel EMT

  • Added Grid Source Block - 3 phase thevenin equivalent block with useful inputs for grid interconnection studies (i.e. short circuit ratio (SCR))

  • Fixed issue where certain voltage and current sources (such as the 1.2/50 8/20 waves) would cause the and steady-state solution to fail

  • Added IEEE/CIGRE .dll PV inverter example, based on the code from the 2023 EPRI paper “Code Based Generic Inverter Based Resource Model”

KPlot

  • Added ability set plot legend position or disable altogether.

2026.4

April 21, 2026

Kestrel EMT

  • Added Comment block, for annotating schematics.

  • Added Transformer circuit component which supports entry of typical transformer test parameters including short circuit impedance and excitation current.

  • Breaking Change the previous “Transformer” component has been renamed to “Ideal Transformer”

  • Improved handling of opening corrupted circuit files (.kcf files)

  • Fixed bug where re-configuring a component (e.g. changing the number of phases in a resistor) would not propagate the monitored quantities correctly (e.g. current or voltage)

  • Fixed bug where monitoring probes placed on individual phases of a three phase node would sometimes fail.

  • Updated graphic for the Constant block.

KPlot

  • Added support for plotting CSV files. CSV files should be comma delimted, only contain numerical data, and the column that represents the x axis should be called “time”

  • Added support for plotting PSCAD .inf/.out files. When using the tool, load the .inf file (not the .out file(s)).

  • Added loading and exporting of plot definitions

  • Added “Format Plot” tab to modify plot title and axis labels

  • Added “Export Plots” which exports all active plots. This replaces the “Save Image” button

2025.11

November 30, 2025

Kestrel EMT

  • Added preliminary IEEE/CIGRE B4.82 Working Group .dll support. Users may now configure external .dll models using the Project Settings menu. All model parameters must be float64. Support for other datatypes coming soon.

  • Added option for replacing single phase or uncoupled three phase transmission lines with a Pi equivalent if the timestep is too short.

  • Replaced separate Add/Subtract/Multiply/Divide blocks with a single Arithmetic block with configurable input polarities and 1 or 3 phase I/O.

  • Updated packaged Python version to 3.12

  • Voltage source now includes IEEE Std C62.45 8/20 us and 1.2/50 us switching waveforms

  • Added GAIN block – multiply inputs by a constant.

  • Different Run Names are now stored in separate files to improve memory efficiency

  • Improved Python block error handling.

  • Fixed bug where Python de-initialization would cause the application to take a long time to close.

  • Help is now searchable HTML instead of .pdf

  • General performance improvements

KPlot

  • Multiple file input is now supported with the “File Manager” sidebar. Load results from multiple files and compare them side by side.

  • Support for Siemens PTI PSSE .out files and KGRID .raw (point on wave) data added.

  • Improved memory effiency and performance

  • Minor interface improvements

  • Help is now searchable HTMl instead of .pdf

2024.8

August 30, 2024

We’re switching to a calendar-based versioning structure to improve clarity.

General

  • KPlot has been split out as its own exe and can open properly formatted hdf5 files on its own without opening the Kestrel EMT GUI

  • Fixed minor bugs relating to the Python module’s error reporting during failed simulations.

v0.94

January 16, 2024

General

  • New KCF file format– Human-readable XML

  • Command Line Version (“KestrelCLI.exe”) added

  • PDF Documentation added

  • Example circuits added (in the sample_kcf folder)

  • Python blocks may optionally share context (i.e. variables and functions) via user selectable “Python Scope” parameter.

  • Python block updated to allow for 23 Inputs/12 Outputs in the GUI

  • User may define sim_end() in the Python block at end of simulation

  • Added KPlot button to open other HDF5 files

  • Bugfix: Fixed issue where running a simulation with only Math blocks fails

  • Bugfix: Fixed issue where HDF5 files are left open after a failed simulation

v0.92

August 12, 2022

General

  • Added ArresterWorks lightning arrester model.

  • Added Varistor V/I Curve plotting in parameter menu.

v0.91

December 5, 2021

General

  • Fixed an issue where upgrading Windows versions could invalidate the software license.

  • MATLAB and Python code blocks can now use a set “Call Rate” to drastically improve performance in circumstances where the code does not need to be executed every timestep.

  • Improved numerical core performance.

  • Individual pole control on time switches.

  • Phasor and RMS blocks now have a “nPerCycle” parameter to drastically improve performance in small timestep simulations.

  • Coupled RL circuits now have a X/Reactance input option

  • Minor interface improvements