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PSS®E Static

Introduction​

The PSS®E Static Node performs static study simulations which are powered by PSS®E, a 3rd party power systems software. It leverages the following PSS®E modules:

  • Power Flow
  • Short Circuit

This Node is typically used for the following:

  • Completing static studies (e.g. investigating thermal loading of an asset pre and post a variety of contingencies).
  • Setting up cases for dynamic studies (e.g. creating a case for a specific active power set point as part of a test).
info

The following PSS®E versions are currently supported:

  • PSS®E v34.4+
  • PSS®E v35

User inputs​

Select model​

Model​

Defines the input directory and file name of the PSS®E Case file, including the .sav file extension.

Example:

sunny-solar-farm\SMIB.sav
note

File paths are relative to the Engine's 'inputs' directory, as defined by the Engine configuration parameter dirs.inputs. For example, if dirs.inputs was set as C:\Users\johnsmith\gridmo\Inputs\:

Absolute file pathRelative file path (required by gridmo)
C:\Users\johnsmith\gridmo\Inputs\sunny-solar-farm\SMIB.savsunny-solar-farm\SMIB.sav

Define simulation​

This allows you to merge your Model into a network model. If enabled, this merge process is completed before the Commands are applied.

Network model​

Defines the input directory and file name of the PSS®E Case file, including the .sav file extension.

Example:

network-model/case.sav

Model: Bus number​

Defines the bus number in the Model at which the network model is merged.

Example:

100

Network model: Bus number​

Defines the bus number in the Network model at which the model is merged.

Example:

30000

Commands​

Defines the Commands which configure the static simulation.

Supported Commands:

  • ADD: Adds a new type of network element (e.g. load).
  • SET: Sets the status or value of a network element (e.g. bus, line, generator).
  • CONTROL: Controls a network element.
  • SOLVE: Solves the static case, considering all previous SET and CONTROL Commands.
  • OUTPUT: Outputs a value as an Internode Variable.
info

All SET and CONTROL Commands preceding a SOLVE Command are applied at the same time when the SOLVE Command is used. Multiple SOLVE Commands are supported and can be used when you want to apply SET and CONTROL Commands sequentially. For example:

SET COMMAND 1
SET COMMANDS 2
CONTROL COMMAND 1
SOLVE
CONTROL COMMAND 2
SOLVE

This following two static solves will occur:

  1. Solve considering SET COMMAND 1, SET COMMAND 2 and CONTROL COMMAND 1; then
  2. Solve considering CONTROL COMMAND 2.

Advanced​

PSS®E version​

Defines the PSS®E version used for the Node. Defaults to Engine configuration.

PSS®E Python API​

Defines the PSS®E API version used for the Node. Defaults to Engine configuration.

Advanced Parameters​

Advanced Parameters allow users to configure test details which are not commonly used. Advanced Parameters are often specific to each Node type.

Each line represents a new Advanced Parameter and is entered as a=b format, where a is the name of the Parameter and b is the corresponding value. All Advanced Parameters are set to their default values if they are not included in the Advanced Parameters field.

Example: Set Advanced Parameter, sample.parameter to a value of 5.

sample.parameter=5

API Reference​

This section details the Commands and Advanced Parameters specific to the Node.

tip

Lines are defined using the following syntax: from->to#id. When completing SMIB studies, we recommend always having the 'to' bus closer to the connection point. Note that the 'from' and 'to' definitions used in Commands (i.e. from->to#id) don't necessarily need to match the .sav case.

ADD Command​

Add load​

ADD, TYPE=LOAD, BUS=, P=, Q=, YP=, YQ=

Adds a load network element at a bus.

Arguments:

  • ADD
  • TYPE (str): Network element type. Set as LOAD.
  • BUS (int): Bus number.
  • P (float): Constant active power [MW].
  • Q (float): Constant reactive power [MVAr].
  • YP (float): Constant admittance active power [MW].
  • YQ (float): Constant admittance reactive power [MVAr].

At least one of P=, Q=, YP= or YQ= must be specified. Any unspecified values default to 0.

Example: Add a 25 MW, 5 MVAr load at bus 400.

ADD, TYPE=LOAD, BUS=400, P=25, Q=5
note

Added loads have a PSS®E ID of Gx where x is an integer. For example:

  • The Command ADD, BUS=100, P=10 creates a load with identifier 100#G1.
  • If a second ADD, BUS=100, P=10 Command was used, a new load with identifier 100#G2 would be created.

SET Command​

Set bus​

SET, BUS=, [BUS=], STATUS=

Sets the status of a bus.

Arguments:

  • SET
  • BUS (int): Bus number.
  • BUS (int)[Optional]: Additional bus numbers.
  • STATUS (str): Bus status. Options:
    • STATUS=IN: Status is in-service.
    • STATUS=OUT: Status is out of service.
    • STATUS=1: Explicitly set bus type code as 1 (i.e. Non-Gen Bus).
    • STATUS=2: Explicitly set bus type code as 2 (i.e. Generator Bus).
    • STATUS=3: Explicitly set bus type code as 3 (i.e. Swing bus).
    • STATUS=4: Explicitly set bus type code as 4 (i.e. Disconnected).
note

We recommend using STATUS=IN and STATUS=OUT Arguments. Explicitly setting the bus type code is not recommended since it doesn't consider what assets are connected to the selected bus.

Example: Set bus 100 out of service.

SET, BUS=100, STATUS=OUT

Set line​

SET, LINE=, [LINE=], STATUS=, [SCR=, XR=]

Sets the status and impedance of a line.

Arguments:

  • SET
  • LINE (pas): Line definition. Lines are defined using the following syntax: from->to#id.
  • LINE (pas)[Optional]: Additional line definitions (only if using STATUS=, SCR= and XR= arguments only support one line)
  • STATUS (str): Line status. Options:
    • STATUS=IN: Status is in-service.
    • STATUS=OUT: Status is out of service.
  • SCR (float)[Optional]:
    • SCR=X (where X is a number): Sets the impedance of the given line to the equivalent Thévenin impedance based on the Project's rated active power [MW], the line voltage and the specified SCR and X/R ratio.
    • SCR=INF: Sets the impedance of the given line to the minimum impedance value applicable in PSS®E (i.e. 1e-5 on system base). XR= Argument is ignored.
  • XR (float)[Optional]: Sets the impedance of the given line to the equivalent Thévenin impedance based on the Project's rated active power [MW], the line voltage and the specified SCR and X/R ratio.
note

SCR and XR Arguments must be used together. These Arguments are typically only used in SMIB studies and are used to calculate the Thévenin equivalent source impedance of the infinite generator.

Example: Set the impedance of the line from bus 800 to bus 900 which has an ID of 1. The line impedance should represent the system Thévenin equivalent impedance for an SCR of 3 and X/R ratio of 2.

SET, LINE=800->900#1, STATUS=IN, SCR=3, XR=2

Example: Set the impedance of the line from bus 1000 to bus 999 with ID 1 to near-zero impedance (infinite system strength), noting that XR= Argument is ignored.

SET, LINE=1000->999#1, STATUS=IN, SCR=INF, XR=1

Set transformer​

SET, TX=, STATUS=, [TAPRATIO=, WINDING=]

Sets the status of a transformer.

Arguments:

  • SET
  • TX (pas): Transformer definition. Transformers are defined using the following syntax: bus1->bus2#id (two-winding transformer) or bus1->bus2->bus3#id (three-winding transformer).
  • STATUS (str): Transformer status. Options:
    • STATUS=IN: Status is in-service.
    • STATUS=OUT: Status is out of service.
  • TAPRATIO (float)[Optional]: Sets the tap ratio of the specified winding number. The control mode of the transformer will be set to "None" to ensure the set tap ratio is maintained irrespective of whether SOLVE, LOCKTAPS=NO is used.
  • WINDING (int)[Optional]: The winding number used when setting the tap ratio. Options:
    • WINDING=1: Winding number 1.
    • WINDING=2: Winding number 2.
    • WINDING=3: Winding number 3 (only applicable for three-winding transformers).

Example: Set the three-winding transformer in-service which is located between bus 100, bus 200, and bus 300 and which has an ID of 1.

SET, TX=100->200->300#1, STATUS=IN

Example: Set the tap position of winding one of the two-winding transformer to 0.975 which is located between bus 100 and bus 200 and which has an ID of 1.

SET, TX=100->200#1, STATUS=IN, TAPRATIO=0.975, WINDING=1
note

Setting the tap ratio assumes that the transformer winding I/O code is in p.u., not kV.

Set generator​

SET, GEN=, [GEN=], STATUS=

Sets the status or active/reactive power limits of a generator.

Arguments:

  • SET
  • GEN (pas): Generator definition. Generators are defined using the following syntax: bus#id.
  • GEN (pas)[Optional]: Additional generator definitions.
  • STATUS (str): Generator status. Options:
    • STATUS=IN: Status is in-service.
    • STATUS=OUT: Status is out of service.
  • QMAX (float)[Optional]: Maximum reactive power capability of the generator [MVAr].
  • QMIN (float)[Optional]: Minimum reactive power capability of the generator [MVAr].
  • PMAX (float)[Optional]: Maximum active power capability of the generator [MW].
  • PMIN (float)[Optional]: Minimum active power capability of the generator [MW].
  • MBASE (float)[Optional]: Base MVA of the generator [MVA]
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to QMAX, QMIN, PMAX and PMIN (i.e. PMAX x VALSCALE). Default value is 1.

Example: Set the generator out of service which is located at bus 100 which has an ID of 1.

SET, GEN=100#1, STATUS=OUT

Example: Set the aggregated generator at bus 150 with id 1 active power min and maximum range to -1.5 MW (for example, to represent a synchronous machine operating in synchronous condenser mode).

SET, GEN=150#1, PMIN=-1.5, PMAX=-1.5

Set load​

SET, LOAD=, STATUS=

Sets the status of a load.

Arguments:

  • SET
  • LOAD (pas): Load definition. Loads are defined using the following syntax: bus#id.
  • STATUS (str): Load status. Options:
    • STATUS=IN: Status is in-service.
    • STATUS=OUT: Status is out of service.

Example: Set the load out of service which is located at bus 100 and which has an ID of 2.

SET, LOAD=100#2, STATUS=OUT

Set fixed shunt​

SET, FSHUNT=, STATUS=

Sets the status of a fixed shunt.

Arguments:

  • SET
  • FSHUNT (pas): Fixed shunt definition. Fixed shunts are defined using the following syntax: bus#id.
  • STATUS (str): Fixed shunt status. Options:
    • STATUS=IN: Status is in-service.
    • STATUS=OUT: Status is out of service.
note

In PSS®E, fixed shunts are different network elements to loads.

Example: Set the fixed shunt out of service which is located at bus 200 and which has an ID of 3.

SET, FSHUNT=200#3, STATUS=OUT

CONTROL Command​

Control Commands are additional solution requirements added to the convergence algorithm which is initiated by the SOLVE Command. These Commands typically cover functionality which is not natively supported by PSS®E. A SOLVE Command is required for preceding CONTROL Commands to be considered.

note

CONTROL Commands are reset after each SOLVE Command is used. If you want a CONTROL Command to be used it must precede each SOLVE Command. For a Node with multiple SOLVE Commands, this may require repeating the CONTROL Command. For example:

SET COMMAND 1
CONTROL COMMAND 1
SOLVE
SET COMMAND 2
SOLVE
CONTROL COMMAND 1
SOLVE

This following three static solves will occur:

  1. Solve considering SET COMMAND 1 and CONTROL COMMAND 1; then
  2. Solve considering SET COMMAND 2; then
  3. Solve considering CONTROL COMMAND 1.
note

You can control multiple generators by using multiple GEN= arguments. If more than one generator specified, the active/reactive power requirement will be shared between the generators based on the ratio of the respective generators' rated MVA.

Control generator - Direct voltage control​

CONTROL, GEN=, [GEN=], Q=VDIRECT, QMIN=, QMAX=, ATBUS=, [VALSCALE=1], VTARGET=

Controls one or more generators using direct voltage control (not voltage droop control).

Arguments:

  • CONTROL
  • GEN (pas): Generator definition. Generators are defined using the following syntax: bus#id.
  • GEN (pas)[Optional]: Additional generator definitions. Generators are defined using the following syntax: bus#id.
  • Q (str): Reactive power control methodology. Set as VDIRECT.
  • QMIN (float): Minimum reactive power capability of the generator [MVAr].
  • QMAX (float): Maximum reactive power capability of the generator [MVAr].
  • ATBUS (int): Bus number which has the target voltage.
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to VTARGET (i.e. VTARGET x VALSCALE). Default value is 1.
  • VTARGET (float)[Optional]: Target voltage set point [p.u.]. Default value is the voltage specified in the Schedu Voltage field (within Plant Data) for the specified generator.

Example: Control the generator at bus 100 which has an ID of 1. The control is direct voltage control of bus 300 with a target voltage of 1.01 [p.u.]. The generator can supply reactive power between -10 MVAr and +15 MVAr.

CONTROL, GEN=100#1, Q=VDIRECT, QMIN=-10, QMAX=15, ATBUS=300, VTARGET=1.01

Control generator - Droop voltage control​

CONTROL, GEN=, [GEN=], Q=VDROOP, QBASE=, DROOP%=, DEADBAND=, [QMIN=, QMAX=], ATBUS=, ATLINE=, [METERBUS =, VALSCALE=1], VTARGET=

Controls one or more generators using voltage droop control. If the measured voltage is larger/smaller than the voltage target + deadband, the specified generators will be controlled to absorb/supply reactive power equal to the droop percentage of QBASE for every 1% the measured voltage is above the voltage target + deadband.

voltage droop characteristic with a deadband and fixed maximum and minimum reactive power limits

Arguments:

  • CONTROL
  • GEN (pas): Generator definition. Generators are defined using the following syntax: bus#id.
  • GEN (pas)[Optional]: Additional generator definitions. Generators are defined using the following syntax: bus#id.
  • Q (str): Reactive power control methodology. Set as VDROOP.
  • QBASE (float): Base reactive power [MVAr].
  • DROOP% (float): Droop percentage [%].
  • DEADBAND (float): Voltage deadband [p.u.].
  • QMIN (int)[Optional]: Minimum reactive power limit at the ATLINE= line [MVAr]. Default value is -∞.
  • QMAX (int)[Optional]: Maximum reactive power limit at the ATLINE= line [MVAr]. Default value is ∞.
  • ATBUS (int): Bus number which has the target voltage.
  • ATLINE (pas): Line which is used for measuring the reactive power. Lines are defined using the following syntax: from->to#id.
  • METERBUS (int)[Optional]: Bus number which is the metering point for the ATLINE= line. Default value is the 'from' bus number as per the ATLINE= argument.
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to VTARGET (i.e. VTARGET x VALSCALE). Default value is 1.
  • VTARGET (float): Target voltage set point [p.u.]. Default value is the voltage specified in the Schedu Voltage field (within Plant Data) for the specified generator.

Example: A PPC exists between bus 600 and bus 700 (ID=1) and is controlling a generator at bus 100 which has an ID of 1. The PPC is acting in voltage droop control with a target voltage of 1.01 [p.u.] at bus 600, a QBASE of 50 MVAr, a droop percentage of 4% and a voltage deadband of 0.01 [p.u.].

CONTROL, GEN=100#1, Q=VDROOP, QBASE=50, DROOP%=4, DEADBAND=0.01, ATBUS=600, ATLINE=600->700#1, VTARGET=1.01

Control generator - Fixed reactive power control​

CONTROL, GEN=, [GEN=], Q=FIXED, ATLINE=, [METERBUS=, VALSCALE=1], QTARGET=

Controls one or more generators using fixed reactive power control. The reactive power target will be applied across the specified line.

Arguments:

  • CONTROL
  • GEN (pas): Generator definition. Generators are defined using the following syntax: bus#id.
  • GEN (pas)[Optional]: Additional generator definitions. Generators are defined using the following syntax: bus#id.
  • Q (str): Reactive power control methodology. Set as FIXED.
  • ATLINE: Location of the target reactive power. Options:
    • ATLINE=TERMINALS: Reactive power target is regulated at the generator terminals.
    • ATLINE=from->to#id (pas): Reactive power target is regulated across the specified line. Lines are defined using the following syntax: from->to#id.
  • METERBUS (int)[Optional]: Bus number which is the metering point for the ATLINE= line. Default value is the 'from' bus number as per the ATLINE= argument.
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to QTARGET (i.e. QTARGET x VALSCALE). Default value is 1.
  • QTARGET (float): Target reactive power set point [MVAr].

Example: Control the generator at bus 100 which has an ID of 1. The control mode is fixed reactive power control regulating -20 MVAr across the line from bus 400 to bus 500 (measured at the 'to-side') which has an ID of 1.

CONTROL, GEN=100#1, Q=FIXED, ATLINE=400->500#1, METERBUS=500, QTARGET=-20

Control generator - Power factor control​

CONTROL, GEN=, [GEN=], Q=PF, ATLINE=, [METERBUS=, VALSCALE=1], PFTARGET=

Controls one or more generators using power factor power control.

Arguments:

  • CONTROL
  • GEN (pas): Generator definition. Generators are defined using the following syntax: bus#id.
  • GEN (pas)[Optional]: Additional generator definitions. Generators are defined using the following syntax: bus#id.
  • Q (str): Reactive power control methodology. Set as PF.
  • ATLINE: Location of the target power factor. Options:
    • ATLINE=TERMINALS: Power factor target is regulated at the generator terminals.
    • ATLINE=from->to#id (pas): Power factor target is regulated across the specified line. Lines are defined using the following syntax: from->to#id.
  • METERBUS (int)[Optional]: Bus number which is the metering point for the ATLINE= line. Default value is the 'from' bus number as per the ATLINE= argument.
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to PFTARGET (i.e. PFTARGET x VALSCALE). Default value is 1.
  • PFTARGET (float): Target power factor set point.

Example: Control the generator at bus 100 which has an ID of 1. The control is power factor control of -0.97 at the generator terminals.

CONTROL, GEN=100#1, Q=PF, ATLINE=TERMINALS, PFTARGET=-0.97

Control generator - Active power control​

CONTROL, GEN=, [GEN=], ATLINE=, [METERBUS=, VALSCALE=1], P=

Controls the active power of one or more generators.

Arguments:

  • CONTROL
  • GEN (pas): Generator definition. Generators are defined using the following syntax: bus#id.
  • GEN (pas)[Optional]: Additional generator definitions. Generators are defined using the following syntax: bus#id.
  • ATLINE Location of the target active power. Options:
    • ATLINE=TERMINALS: Active power target is regulated at the generator terminals.
    • ATLINE=from->to#id (pas): Active power target is regulated across the specified line. Lines are defined using the following syntax: from->to#id.
  • METERBUS (int)[Optional]: Bus number which is the metering point for the ATLINE= line. Default value is the 'from' bus number as per the ATLINE= argument.
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to P (i.e. P x VALSCALE). Default value is 1.
  • P (float): Active power target [MW].

Example: A PPC has a target active power set point and is controlling two generators at bus 100 (ID=1) and bus 200 (ID=1). The active power set point is 95 MW and is applied across the line from bus 400 to bus 500 (measured at the 'from-side') which has an ID of 1.

CONTROL, GEN=100#1, GEN=200#1, ATLINE=400->500#1, P=95

Control load - Fixed reactive power control​

CONTROL, LOAD=, Q=FIXED, ATLINE=, [METERBUS=, VALSCALE=1], QTARGET/YQTARGET=

Controls a load/shunt using fixed reactive power control.

Arguments:

  • CONTROL
  • LOAD (pas): Load/shunt definition. Loads and shunts are defined using the following syntax: bus#id.
  • Q (str): Reactive power control methodology. Set as FIXED.
  • Target reactive power set point. Options:
    • QTARGET= (float): Target reactive power set point [MVAr] for constant power load; or
    • YQTARGET= (float): Target reactive power set point [MVAr] for constant admittance load.
  • ATLINE Location of the target active power. Options:
    • ATLINE=TERMINALS: Reactive power target is regulated at the generator terminals.
    • ATLINE=from->to#id (pas): Reactive power target is regulated across the specified line. Lines are defined using the following syntax: from->to#id.
  • METERBUS (int)[Optional]: Bus number which is the metering point for the ATLINE= line. Default value is the 'from' bus number as per the ATLINE= argument.
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to QTARGET (i.e. QTARGET x VALSCALE). Default value is 1.
note

Only one LOAD= argument is supported per Command.

Example: Control the load at bus 100 which has an ID of 1. The control mode is fixed reactive power control of -10 MVAr across the line from bus 400 to bus 500 (measured at the 'from-side') which has an ID of 1.

CONTROL, LOAD=100#1, Q=FIXED, ATLINE=400->500#1, QTARGET=-10

Control load - Power factor control​

CONTROL, LOAD=, Q=PF, ATLINE=, [METERBUS=, VALSCALE=1], PFTARGET=

Controls a load/shunt using power factor control.

Arguments:

  • CONTROL
  • LOAD (pas): Load/shunt definition. Loads and shunts are defined using the following syntax: bus#id.
  • Q (str): Reactive power control methodology. Set as PF.
  • ATLINE Location of the target power factor. Options:
    • ATLINE=TERMINALS: Power factor target is regulated at the generator terminals.
    • ATLINE=from->to#id (pas): Power factor target is regulated across the specified line. Lines are defined using the following syntax: from->to#id.
  • METERBUS (int)[Optional]: Bus number which is the metering point for the ATLINE= line. Default value is the 'from' bus number as per the ATLINE= argument.
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to PFTARGET (i.e. PFTARGET x VALSCALE). Default value is 1.
  • PFTARGET (float): Target power factor power set point.
note

Only one LOAD= argument is supported per Command.

Example: Control the load at bus 100 which has an ID of 1. The control is power factor control of -0.97 at the load terminals.

CONTROL, LOAD=100#1, Q=PF, ATLINE=TERMINALS, PFTARGET=-0.97

Control load - Active power control​

CONTROL, LOAD=, ATLINE=, [METERBUS=, VALSCALE=1], P/YP=

Controls the active power of a load/shunt.

Arguments:

  • CONTROL
  • LOAD (pas): Load/shunt definition. Loads and shunts are defined using the following syntax: bus#id.
  • Load setpoint. Options:
    • P (float): Active power target [MW] for constant power load; or
    • YP (float): Active power target [MW] for constant admittance load.
  • ATLINE Location of the target active power. Options:
    • ATLINE=TERMINALS: Active power target is regulated at the generator terminals.
    • ATLINE=from->to#id (pas): Active power target is regulated across the specified line. Lines are defined using the following syntax: from->to#id.
  • METERBUS (int)[Optional]: Bus number which is the metering point for the ATLINE= line. Default value is the 'from' bus number as per the ATLINE= argument.
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to P (i.e. P x VALSCALE). Default value is 1.
note

Only one LOAD= argument is supported per Command.

Example: Control the load at bus 100 which has an ID of 1. The active power set point is 22 MW and is applied across load terminals.

CONTROL, LOAD=100#1, ATLINE=TERMINALS, P=22

SOLVE Command​

SOLVE, [LOCKTAPS=, LOCKSHUNTS=]

Solves the static case, considering all previous SET and CONTROL Commands.

Arguments:

  • SOLVE
  • LOCKTAPS (str)[Optional]: Solution option specifying whether the position of transformer taps may change during the solution. Defaults to NO. Options:
    • LOCKTAPS=YES: Transformer taps are locked.
    • LOCKTAPS=NO: Transformer taps are unlocked (stepped taps).
  • LOCKSHUNTS (str)[Optional]: Solution option specifying whether the position of switched shunts may change during the solution. Defaults to NO. Options:
    • LOCKSHUNTS=YES: Switched shunt positions are locked.
    • LOCKSHUNTS=NO: Switched shunt positions are unlocked (stepped shunt steps).

Example: Solve the case where transformer taps are not locked and where switched shunt positions are locked.

SOLVE, LOCKTAPS=NO, LOCKSHUNTS=YES

OUTPUT Command​

note

Only one value can be output per OUTPUT Command.

info

The Node automatically outputs .sav cases ready for use by connected PSS®E Dynamic Nodes. Therefore, you don't need to specify this output.

Output bus value​

OUTPUT, BUS=, VAL=, [VALSCALE=1], NAME=

Outputs a value from a bus.

Arguments:

  • OUTPUT
  • BUS (int): Bus number.
  • VAL (str): Bus value. Options:
    • VAL=V: Voltage [p.u.].
    • VAL=VKV: Voltage [kV].
    • VAL=ANGLE: Angle [degrees].
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to the output value (i.e. scaled_output = VAL x VALSCALE). Default value is 1.
  • NAME (str): Output name. Output names must be unique within a Node.

Example: Output the voltage [p.u] at bus 100 and name the Internode Variable 'busvolts'.

OUTPUT, BUS=100, VAL=V, NAME=i_busvolts

Output line value​

OUTPUT, LINE=, VAL=, [METERBUS=, VALSCALE=1], NAME=

Outputs a value from a line.

Arguments:

  • OUTPUT
  • LINE (pas): Line definition. Lines are defined using the following syntax: from->to#id. Values are output at the 'from-side' of the line.
  • VAL (str): Line value. Options:
  • METERBUS (int)[Optional]: Bus number which is the metering point for the LINE= line. Default value is the 'from' bus number as per the LINE= argument.
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to the output value (i.e. scaled_output = VAL x VALSCALE). Default value is 1.
  • NAME (str): Output name. Output names must be unique within a Node.

Example: Output the active power flowing through the line from bus 100 to bus 200 (measured at the 'from-side') which has an ID of 1. Name the Internode Variable 'p_at_line'.

OUTPUT, LINE=100->200#1, VAL=P, NAME=i_p_at_line

Output transformer value​

OUTPUT, TX=, VAL=, [METERBUS=, VALSCALE=1], NAME=

Outputs a value from a transformer.

Arguments:

  • OUTPUT
  • TX (pas): Transformer definition. Transformers are defined using the following syntax: bus1->bus2#id (two-winding transformer) or bus1->bus2->bus3#id (three-winding transformer).
  • VAL (str): Transformer value. Options:
    • VAL=P: Active power [MW].
    • VAL=Q: Reactive power [MVAr].
    • VAL=S: Apparent power [MVA].
    • VAL=PF: Power factor (generator convention, P/S) [unitless]. Click here for details on how gridmo calculates power factor.
    • VAL=TAPRATIO: Tap ratio of the winding with the highest base voltage - as this is most likely where the tap changer is present (decimal, such as 0.90 meaning 90% of default tap) [unitless].
    • VAL=LOAD%: Thermal loading using the 'RATE1' field [%].
  • METERBUS (int)[Optional]: Bus number which is the metering point for the TX= line. Default value is the 'from' bus number as per the TX= argument.
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to the output value (i.e. scaled_output = VAL x VALSCALE). Default value is 1.
  • NAME (str): Output name. Output names must be unique within a Node.

Example: Output the apparent power flowing through the transformer located between bus 100 to bus 200 which has an ID of 2. Name the Internode Variable i_tx_sload.

OUTPUT, TX=100->200#2, VAL=S, NAME=i_tx_sload

Output generator value​

OUTPUT, GEN=, VAL=, [VALSCALE=1], NAME=

Outputs a value from a generator.

Arguments:

  • OUTPUT
  • GEN (pas): Generator definition. Generators are defined using the following syntax: bus#id.
  • VAL (str): Generator value. Options:
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to the output value (i.e. scaled_output = VAL x VALSCALE). Default value is 1.
  • NAME (str): Output name. Output names must be unique within a Node.

Example: Output the reactive power flowing through the generator located at bus 100 which has an ID of 1. Name the Internode Variable 'generator-Q'.

OUTPUT, GEN=100#1, VAL=Q, NAME=i_gen_terminal_q

Output voltage droop target value​

OUTPUT, VAL=VDROOPTARGET, QBASE=, DROOP%=, DEADBAND=, QMIN=, QMAX=, ATBUS=, ATLINE=, [METERBUS=, VALSCALE=1], NAME=

Outputs the expected target voltage set point [p.u.] for a pre-defined voltage droop characteristic.

Arguments:

  • OUTPUT
  • VAL (str): Voltage droop characteristic value. Options:
    • VAL=VDROOPTARGET: Target voltage set point [p.u.].
  • QBASE (float): Base reactive power [MVAr].
  • DROOP% (float): Droop percentage [%].
  • DEADBAND (float): Voltage deadband [p.u.].
  • QMIN (float): Minimum reactive power limit at the ATLINE= line [MVAr].
  • QMAX (float): Maximum reactive power limit at the ATLINE= line [MVAr].
  • ATBUS (int): Bus number which has the target voltage.
  • ATLINE (pas): Line which is used for measuring the reactive power. Lines are defined using the following syntax: from->to#id.
  • METERBUS (int)[Optional]: Bus number which is the metering point for the ATLINE= line. Default value is the 'from' bus number as per the ATLINE= argument.
  • VALSCALE (float)[Optional]: Multiplicative scaling factor applied to the output value (i.e. scaled_output = VAL x VALSCALE). Default value is 1.
  • NAME (str): Output name. Output names must be unique within a Node.

Example: Output the voltage droop target given the measured voltage at bus 500, the reactive power flow from bus 400 to 500 (id 1) metered at the bus 500 end, using 80 MVAr as the reactive power base, QMAX of 60 MVAr, QMIN of -60 MVAr and with a droop of 6%. Name the Internode Variable i_poc_vdroop_target.

OUTPUT, VAL=VDROOPTARGET, QBASE=80, DROOP%=6, DEADBAND=0, QMIN=-60, QMAX=60, ATBUS=500, ATLINE=400->500#1, METERBUS=500,  NAME=i_poc_vdroop_target

Advanced Parameters​

node.convergence.gain​

  • Description: Defines the proportional gain used by the convergence algorithm. Large generators connected to weak networks with low droop percentages may require a gain lower than default to converge.
  • Type: float
  • Units: N/A
  • Default: 0.2
  • Range: 0.001 - 0.5
node.convergence.gain=value

node.convergence.mva​

  • Description: Defines the acceptable tolerance error in the convergence algorithm. A load/generator is deemed converged when the absolute value of the difference (between actual and target values) is less than this value.
  • Type: float
  • Units: MW or MVAr
  • Default: 0.001
  • Range: 0.001 - 5
node.convergence.mva=value

node.convergence.converge_at_limit​

  • Description: Defines if a generator in a CONTROL Command, which cannot achieve the control target due to hitting its minimum or maximum reactive power limit (as per the PSS®E Case file), is considered converged. For example, a generator is asked to regulate to 22 MVAr, but it can only inject 20 MVAr. If this Advanced Parameter is set to Yes, the generator is treated as converged. If this Advanced Parameter is set to No the generator will prevent the static study solution from converging. Regardless of the setting, an Engine warning is raised if a generator reaches its minimum or maximum reactive power capability.
  • Type: bool
  • Units: N/A
  • Default: Yes
  • Range: Yes, No
node.convergence.converge_at_limit=value

system.convergence.mva​

  • Description: Defines the acceptable whole-network MVA mismatch, equivalent to PSS®E parameter TOLN. A network is deemed converged and stable when the mismatch is less than this value.
  • Type: float
  • Units: MVA
  • Default: 0.5
  • Range: >=0.001
system.convergence.mva=value

max_iter​

  • Description: Defines the acceptable number of iterations during Case file and generator/load control mode convergence. Very sensitive control modes (low droop % values) or weak networks may require higher than default max_iter to converge.
  • Type: int
  • Units: N/A
  • Default: 500
  • Range: 50 - 10000
max_iter=value

voltages.tolerance​

  • Description: Defines the acceptable voltage tolerance for the static study. Voltage regulation schemes are considered on target when the actual voltage is within this value (+/- the voltage tolerance).
  • Type: float
  • Units: p.u.
  • Default: 1e-5
  • Range: 0 - 1
voltages.tolerance=value

voltages.lower​

  • Description: Defines the acceptable lower voltage bound for the static study. Any buses with voltage lower than this value will prevent the case from converging. A network is deemed converged and stable when all in-service buses have per unit voltage higher than this value.
  • Type: float
  • Units: p.u.
  • Default: 0.85
  • Range: 0 - 0.99
voltages.lower=value

voltages.higher​

  • Description: Defines the acceptable upper voltage bound for the static study. Any buses with voltage higher than this value will prevent the case from converging. A network is deemed converged and stable when all in-service buses have per unit voltage lower than this value.
  • Type: float
  • Units: p.u.
  • Default: 1.15
  • Range: 1.01 - 2
voltages.higher=value

system.swingbus.ignorevolt​

  • Description: Should the swing bus (type 3 bus in PSS®E model) be excluded from the voltages.lower and voltages.higher checks? This value defaults to Yes which is typically appropriate for SMIB studies. For full system model studies, setting this value to NO is recommended.
  • Type: bool
  • Units: N/A
  • Default: Yes
  • Range: Yes / No
system.swingbus.ignorevolt=value

low.scr.mode​

  • Description: Enables a low SCR mode where impedance changes (via SET, LINE=, SCR=, XR=) are slowly ramped during a SOLVE command.
  • Type: bool
  • Units: N/A
  • Default: No
  • Range: Yes / No
low.scr.mode=value