Component List

This document outlines the available components in Kestrel EMT.

Note that this page is programatically generated.

Circuitry

Basic Components

Resistor

Ideal resistor model.

Parameters:

  • Input - Resistance or Power

  • Phases - 1-Ø or 3-Ø or 3-Ø Wye or 3-Ø \(\Delta\)

  • Resistance - Resistance in Ohms

  • Voltage - Nominal voltage rating in RMS (line to line for 3-Ø, line to neutral for 1-Ø)

  • Power - Total nominal power rating

Inductor

Ideal inductor model.

Parameters:

  • Phases - 1-Ø or 3-Ø or 3-Ø Wye or 3-Ø \(\Delta\)

  • Input - Inductance (L) or Reactance (X) or Reactive Power (Q)

  • Inductance

  • Reactance - Reactance in Ohms

  • Frequency

  • Voltage - Nominal voltage rating in RMS (line to line for 3-Ø, line to neutral for 1-Ø)

  • Power - Total nominal reactive power rating

  • Frequency

Capacitor

Ideal capacitor model

Parameters:

  • Phases - 1-Ø or 3-Ø or 3-Ø Wye or 3-Ø \(\Delta\)

  • Input - Capacitance (C) or Reactance (X) or Reactive Power (Q)

  • Capacitance

  • Initial_Voltage

  • Reactance - Reactance in Ohms

  • Frequency

  • Voltage - Nominal voltage rating in RMS (line to line for 3-Ø, line to neutral for 1-Ø)

  • Power - Total nominal reactive power rating

  • Frequency

RLC

Combined series RLC model.

Parameters:

  • Phases - 1-Ø or 3-Ø or 3-Ø Wye

  • Resistance

  • Inductance

  • Capacitance

Coupled RL

Coupled 3-Ø series RL model.

Parameters:

  • Input - Inductance (L) or Reactance (X)

  • R1 - Positive Sequence Resistance

  • R0 - Zero Sequence Resistance

  • L0 - Zero Sequence Inductance

  • L1 - Positive Sequence Inductance

  • X0 - Zero Sequence Inductive Reactance

  • X1 - Positive Sequence Inductive Reactance

  • Frequency

Varistor

Nonlinear resistor defined as a piecewise linear function V(i). Characteristic must be monotonically increasing. Negative currents and voltages are not allowed (characteristic is assumed to be symmetric). Do not include the point (0,0). The ArresterWorks Lightning Arrester VI Characteristic is courtesy of Jonathan Woodworth (arresterworks.com).

Parameters:

  • Phases - 1-Ø or 3-Ø or 3-Ø Wye or 3-Ø \(\Delta\)

  • Characteristic - Manual VI or ArresterWorks

  • VI Curve

  • MCOV

  • Class - Light Duty or Normal Duty or Heavy Duty or 5 kA or 10 kA or Station or Class 1 or Class 2 or Class 3 or Class 4 or Class 5

Sources

Voltage Source

Configurable voltage source. The 8/20µs and 1.2/50µs waves are implemented based on IEEE Std C62.45.

Parameters:

  • Waveform - Cosine or Impulse or 8/20µs Wave or 1.2/50µs Wave or DC

  • Phases - 1-Ø or 3-Ø

  • Scaling - VLN RMS or VLL RMS or VLN Peak or VLL Peak

  • Sequence - Zero or Positive or Negative

  • Amplitude - Voltage Amplitude

  • Frequency

  • Phase

  • Ton

  • Resistance

  • Tstart

  • Tstop

  • Tstart

  • Tstop

Grid Source

Configurable 3-Ø source with convenient inputs such as short circuit ratio (SCR). This model is simply a sinusoidal voltage source in series with a series R-L component. NERC PRC-029 voltage ridethrough (VRT) waveforms 1 and 2 correspond to Table 1 (AC-Connected Wind IBR) and Table 2 (All Other IBR) respectively. Playback of the voltage waveform occurs behind the Grid Source impedance, so the voltage at the terminals of the component will differ. The full VRT waveform takes about 15.5 seconds to run.

Parameters:

  • Playback - Flat Run or PRC-029-1 VRT 1 or PRC-029-1 VRT 2

  • Start Time

  • Voltage - Voltage Amplitude

  • Frequency

  • Phase

  • SCR - Short Circuit Ratio

  • P_project - Facility size. SCR and P_project are used to calculate the short circuit strength

  • XR Ratio - Inductive Reactance - Resistance Ratio of the grid equivalent

Current Source

Configurable current source. The 8/20µs and 1.2/50µs waves are implemented based on IEEE Std C62.45.

Parameters:

  • Waveform - Cosine or Impulse or DC or 8/20µs Wave or 1.2/50µs Wave

  • Phases - 1-Ø or 3-Ø

  • Scaling - I RMS or I Peak

  • Sequence - Zero or Positive or Negative

  • Amplitude - Current Amplitude

  • Frequency

  • Phase

  • Ton

  • Tstart

  • Tstop

  • Tstart

  • Tstop

Programmable Source

Source current/voltage is dependent on the input math blocks.

Parameters:

  • Phases - 1-Ø or 3-Ø

  • Source Type - Voltage or Current

  • Resistance

Ground

Ground reference.

Transformers

Ideal Transformer

Ideal transformer (Note: Even transforms DC). Three phase transformers with Wye-\(\Delta\) and \(\Delta\)-Wye have standard ANSI phase shift (primary voltage leads by 30 degrees).

Parameters:

  • Phases - 1-Ø or 3-Ø Wye-Wye or 3-Ø Wye-\(\Delta\) or 3-Ø \(\Delta\)-Wye or 3-Ø \(\Delta\)-\(\Delta\)

  • n - Winding ratio (n:1)

  • Tap Changing

  • Taps - Total number of tap settings.

  • TapSize - Tap size (per unit).

Transformer

Transformer with typical nameplate specified values. Three phase transformers with Wye-\(\Delta\) and \(\Delta\)-Wye have standard ANSI phase shift (primary voltage leads by 30 degrees).

Parameters:

  • Phases - 1-Ø or 3-Ø Wye-Wye or 3-Ø Wye-\(\Delta\) or 3-Ø \(\Delta\)-Wye or 3-Ø \(\Delta\)-\(\Delta\)

  • V1 - Primary Voltage

  • V2 - Secondary Voltage

  • Xs - Series Reactance

  • Rs - Series Resistance

  • Ie - Excitation Current

  • S - XFMR MVA rating, used for impedance calculation only.

  • Frequency - System frequency, used for impedance calculation

  • Taps - Total number of tap settings.

  • TapSize - Tap size (per unit).

Switching

Time Switch

Time programmable switch.

Parameters:

  • Phases - 1-Ø or 3-Ø or 3-Ø Wye

  • Starts Open - Specify whether the switch is open during the steady state solution.

  • Pole Control - Individually control the switch poles.

  • Ron - Series resistance when switch is on (closed).

  • Roff - Series resistance when switch is on (open).

  • I Interrupt - Current threshold for switch interrupting current.

  • Switch Times

  • Switch Times

  • Switch Times A

  • Switch Times B

  • Switch Times C

Controlled Switch

Switch controllable using math blocks. Switch is closed if input is greater than or equal to 1.

Parameters:

  • Phases - 1-Ø or 3-Ø or 3-Ø Wye

  • Ron - Series resistance when switch is on (closed).

  • Roff - Series resistance when switch is on (open).

  • I Interrupt - Current threshold for switch interrupting current.

Diode

Ideal diode (Vd = 0).

Parameters:

  • Auto Snub - Improves numerical stability by inserting a small RC circuit across the diode, dependent on timestep.

Transmission Lines

Transmission Line

Transmission line using Bergeron model.

Parameters:

  • Phases - 1-Ø or 3-Ø or 3-Ø Coupled

  • Length

  • Lp - Series inductance per unit length.

  • Cp - Shunt capacitance per unit length.

  • Rp - Series resistance per unit length.

  • L1 - Series positive sequence inductance per unit length.

  • L0 - Series zero sequence inductance per unit length.

  • C1 - Shunt positive sequence capacitance per unit length.

  • C0 - Shunt zero sequence capacitance per unit length.

  • R1 - Series positive sequence resistance per unit length.

  • R0 - Series zero sequence resistance per unit length.

Math

Basic

Arithmetic

Sum/Subtract/Multiply/Divide multiple inputs.

Parameters:

  • Operation - Sum or Multiply or Divide

  • Phases - 1-Ø or 3-Ø

  • Input1 - Plus or Minus

  • Input2 - Plus or Minus

ABS

Outputs the absolute value of the input.

GAIN

Multiplies the input(s) by a constant

Parameters:

  • Phases - 1-Ø or 3-Ø

  • Gain - Value to scale input by.

TRIG

Standard trigonometric functions. All operate in radians.

Parameters:

  • Function - COS or SIN or TAN or ACOS or ASIN or ATAN

Logic

AND

Digital Logic AND Gate. Outputs 1 if both inputs are greater than or equal to 1.

OR

Digital Logic OR Gate. Outputs 1 if either input is greater than or equal to 1.

NOT

Digital logic NOT Gate. If the input is greater or equal to one, returns 0. If the input is less than one, returns 1.

Greater Than

Greater-Than comparison. Outputs a 1 if the first (top) input is greater than the second input.

Moving Average

Moving Average

Parameters:

  • Time Constant - Time constant

Special Variable

Outputs the value of a special variable, such as the current simulation time.

Parameters:

  • Variable - TIME or DT

Constant

Sets the control input to a constant value.

Parameters:

  • Value - Constant value.

Signal Source

Configurable signal source for control circuits.

Parameters:

  • Waveform - Cosine or Impulse or Square or Arbitrary

  • Amplitude

  • Frequency

  • Frequency

  • Phase

  • Ton

  • Offset - DC Offset of waveform.

  • Offset - DC Offset of waveform.

  • Output

Derivative

First order derivative

Integral

Basic integral

RMS

Calculates the Root-Mean-Square of a signal using a sliding window.

Parameters:

  • Phases - 1-Ø or 3-Ø

  • Frequency - Defines the sliding window size [n= 1/(dt*Frequency)]

  • nPerCycle - Samples per Cycle. Effective sample frequency is Frequency * nPerCycle.

Phasor

Uses a DFT based algorithm to calculate a phasor. Values are reported as a real/imaginary pair if “Polar” is not checked, otherwise amplitude and phase (radians) is reported.

Parameters:

  • Phases - 1-Ø or 3-Ø

  • Frequency - Defines the window size

  • nPerCycle - Samples per Cycle. Effective sample frequency is Frequency * nPerCycle.

  • Polar - If checked, reports values in polar coordinates. Otherwise, cartesian values are reported.

Arg

Converts a Real/Imaginary pair to Amplitude and Phase.

Parameters:

  • Phases - 1-Ø or 3-Ø

Sequence

Sequence Component transformation. Converts phase quantities into the sequence domain (ABC -> 012). Accepts (and outputs) a Real and Imaginary set of three phase inputs and outputs.

Other

Monitor Node

Monitor a node. If placed on a circuit node, the voltage will be monitored. If placed on a math node, its value will be monitored.

Parameters:

  • Measurement - Line-to-Ground or Line-to-Line

Current Measurement

Ideal current measurement / current transformer using 100 µ\(\Omega\) shunt.

Parameters:

  • Phases - 1-Ø or 3-Ø

Node Name

Name a node.

Template Component

Template component used to create subcircuit blocks.

Python Block

Define a function named “func” which will run once per timestep. Put any initialization code outside of this function. The number of input parameters and returns to “func” should match the Num Inputs and Num Outputs. All parameters should be floats. Optionally, the special function “sim_end” may be declared, which will be called once at the end of the simulation.

Parameters:

  • Num Inputs - 0 or 3 or 23

  • Num Outputs - 0 or 3 or 12

  • Call Rate - Specify how frequently to call the Python code in the simulation. Set to Auto to call every timestep (costly).

  • Python Scope - Set to Auto to keep scope separate from other Python Blocks. Python block with the same scope names will share variables and function names.

  • Python Code

MATLAB Block

Define a single function named “func” which will run at the specified Call Rate. Use a single float input array and single float output array regardless of the nubmer of inputs. See documentation for help setting up MATLAB. MATLAB 2024a or above is required.

Parameters:

  • Num Inputs - 0 or 1 or 2 or 3

  • Num Outputs - 0 or 1 or 2 or 3

  • Call Rate - Specify how frequently to call the MATLAB code in the simulation.

  • MATLAB Code

Comment

For Text

Parameters:

  • Text - Any text may go here.

  • Format - Comment or Large Comment or Large Title or Small Title