Series Compensator

The series_compensator object automatically regulates voltage on a distribution line. It sits between two nodes (a "from" node and a "to" node) and works like an adjustable transformer, raising or lowering the downstream voltage to keep it close to a user-defined setpoint on each phase. It supports both standard three-phase and triplex (split-phase) connections, and includes optional features such as frequency-responsive voltage adjustment, configurable control gains and response timing, and an automatic bypass mode that disengages the device when upstream voltage falls outside safe limits.

For technical details on series compensator modeling, see Series Compensator Theory.

Sample

object series_compensator { 
    name ser_comp; // Name of the series compensator
    phases AN;  // In this example the device is a single phase device
    kp 0.4;  // Proportional gain of the voltage controller
    ki 200;  // Integral gain of the voltage controller
    kpf 2;   // proportional gain of the frequency controller
    from 37; // The device is connected between Node 37 and Node 3701
    to 3701; // The device is connected between Node 37 and Node 3701
    f_db_max 0.05;  // Upper limiter of the deadband of the frequency controller, unit: Hz.
    f_db_min -0.05; // Lower limiter of the deadband of the frequency controller, unit: Hz.
    delta_Vmax 0.058; // Upper limiter of the voltage set point, unit: per unit
    delta_Vmin -0.083; // Lower limiter of the voltage set point, unit: per unit
    n_max_ext_A 1.3; // Maximum turn ratio of the series compensator, phase A
    n_max_ext_B 1.3; // Maximum turn ratio of the series compensator, phase B
    n_max_ext_C 1.3; // Maximum turn ratio of the series compensator, phase C
    n_min_ext_A 0.7; // Minimum turn ratio of the series compensator, phase A
    n_min_ext_B 0.7; // Minimum turn ratio of the series compensator, phase B
    n_min_ext_C 0.7; // Minimum turn ratio of the series compensator, phase C
    frequency_regulation true;
}

Series Compensator Parameters

Properties

series_compensator objects are derived from link objects, so any parameters of the link object are available as well.

The I/O column indicates whether a property is user-settable input (I), simulation-computed output (O), or both (IO).

Table 1: series_compensator table 1

Property Name	Type	Unit	I/O	Description
vset_A	double	pu	IO	Voltage magnitude reference for phase A
vset_B	double	pu	IO	Voltage magnitude reference for phase B
vset_C	double	pu	IO	Voltage magnitude reference for phase C
vset_A_0	double	pu	I	Voltage magnitude set point for phase A, changed by the player
vset_B_0	double	pu	I	Voltage magnitude set point for phase B, changed by the player
vset_C_0	double	pu	I	Voltage magnitude set point for phase C, changed by the player
vset_1	double	pu	IO	Voltage magnitude reference for phase 1 of a triplex system
vset_2	double	pu	IO	Voltage magnitude reference for phase 2 of a tryplex system
vset_1_0	double	pu	I	Voltage magnitude reference for phase 1 of a triplex system
vset_2_0	double	pu	I	Voltage magnitude reference for phase 2 of a tryplex system
frequency_regulation	bool	N/A	I	DELTAMODE: Boolean value indicating whether the frequency regulation of the series compensator is enabled or not
frequency_open_loop_control	bool	N/A	I	DELTAMODE: Boolean value indicating whether the frequency open loop control of the series compensator is enabled or not
t_delay	double	N/A	I	The controller will wait for t_delay to take actions
t_hold	double	N/A	I	Once the controller changes the voltage set point, it will stay there for t_hold time
recover_rate	double	N/A	I	The rate that the voltage goes back to nominal, unit: pu/s
frequency_low	double	N/A	I	The low frequency that activates the controller
frequency_high	double	N/A	I	The high frequency that activates the controller
V_error	double	N/A	I	Make sure the voltage can go back to nominal
voltage_update_tolerance	double	pu	I	Largest absolute between vset_X and measured voltage that won't force a reiteration
n_max_ext_A	double	N/A	I	Maximum Turn ratio for phase A
n_max_ext_B	double	N/A	I	Maximum Turn ratio for phase B
n_max_ext_C	double	N/A	I	Maximum Turn ratio for phase C
n_min_ext_A	double	N/A	I	Minimum Turn ratio for phase A
n_min_ext_B	double	N/A	I	Minimum Turn ratio for phase B
n_min_ext_C	double	N/A	I	Minimum Turn ratio for phase C
n_max_ext_1	double	N/A	I	Maximum Turn ratio for phase 1 (triplex)
n_max_ext_2	double	N/A	I	Maximum Turn ratio for phase 2 (triplex)
n_min_ext_1	double	N/A	I	Minimum Turn ratio for phase 1 (triplex)
n_min_ext_2	double	N/A	I	Minimum Turn ratio for phase 2 (triplex)
kp	double	N/A	I	Proportional gain
ki	double	N/A	I	Integrator gain
kpf	double	N/A	I	Proportional gain of frequency regulation
f_db_max	double	N/A	I	Frequency dead band max
f_db_min	double	N/A	I	Frequency dead band min
delta_Vmax	double	N/A	I	Upper limit of the frequency regulation output
delta_Vmin	double	N/A	I	Lower limit of the frequency regulation output
delta_V	double	N/A	O	Frequency regulation output
V_bypass_max_pu	double	N/A	I	The upper limit voltage to bypass compensator
V_bypass_min_pu	double	N/A	I	The lower limit voltage to bypass compensator
phase_A_state	enumeration	N/A	IO	Defines if phase A is in bypass or not Valid values: NORMAL, BYPASS.
phase_B_state	enumeration	N/A	IO	Defines if phase B is in bypass or not Valid values: NORMAL, BYPASS.
phase_C_state	enumeration	N/A	IO	Defines if phase C is in bypass or not Valid values: NORMAL, BYPASS.
phase_1_state	enumeration	N/A	IO	Defines if phase 1 is in bypass or not Valid values: NORMAL, BYPASS.
phase_2_state	enumeration	N/A	IO	Defines if phase 2 is in bypass or not Valid values: NORMAL, BYPASS.
series_compensator_resistance	double	Ohm	I	Baseline resistance for the series compensator device - needed for NR

Internal Properties

Internal Properties

These properties are published with PA_HIDDEN and are intended for internal or developer use.

Table 2: series_compensator table 2

Property Name	Type	Unit	I/O	Description
turns_ratio_A	double	N/A	O	Debug variable - Turns ratio for phase A series compensator equivalent
turns_ratio_B	double	N/A	O	Debug variable - Turns ratio for phase B series compensator equivalent
turns_ratio_C	double	N/A	O	Debug variable - Turns ratio for phase C series compensator equivalent
turns_ratio_1	double	N/A	O	Debug variable - Turns ratio for phase 1 (triplex) series compensator equivalent
turns_ratio_2	double	N/A	O	Debug variable - Turns ratio for phase 2 (triplex) series compensator equivalent