Triplex Load

Triplex load is similar to load and ZIPload in that load can be specified as a direct value, or as a base load, then a ZIP fraction applied to that base load. The load can be placed on phase 1 (120V), phase 2 (120V) or phase 12 (240V). Much like the load object, player objects can be used to vary the load with time. triplex_load objects provide a means to implement constant current, constant power, and constant impedance losses or generation into the system. The convention is a load is a positive quantity, so generation would need to be represented as a negative number.

Example Triplex Load

Loads can be a mixture of the constant current, constant impedance, and constant power types. A typical, mixed load would be implemented as

object triplex_load {
    phases "AS";
    name tplex_load;
    constant_current_1 -0.586139+9.765222j;
    constant_impedance_2 221.915014+104.430595j;
    constant_power_12 4200.00+2100.00j;
    nominal_voltage 120.0;
    }

Triplex Load Parameters

triplex_load objects are derived from triplex_node objects, so any parameters of the triplex_node 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).

General Properties

Table 1: triplex_load table 1
Property Name	Type	Unit	I/O	Description
load_class	enumeration	N/A	I	Describes the type of load the object represents. Used for informational purposes only. Valid types may be referenced by keyword or number 0 - `U` - Unknown load type 1 - `R` - Residential load 2 - `C` - Commercial load 3 - `I` - Industrial load 4 - `A` - Agricultural load
load_priority	enumeration	N/A	I	Load classification based on priority. Valid values: `DISCRETIONARY`, `PRIORITY`, `CRITICAL`.

ZIP Load Properties

These properties define constant power, constant current, and constant impedance loads directly. The _1, _2, and _12 variants represent loads on phase 1 (to neutral), phase 2 (to neutral), and phase 12 (between phases/delta) respectively. The _real and _reac suffixed variants provide access to the real and imaginary components individually.

Table 2: triplex_load table 2
Property Name	Type	Unit	I/O	Description
constant_power_1	complex	VA	IO	Constant power load on phase 1 (to neutral).
constant_power_2	complex	VA	IO	Constant power load on phase 2 (to neutral).
constant_power_12	complex	VA	IO	Constant power load on phase 12 (between phases, delta connection).
constant_power_1_real	double	W	IO	Constant power load on phase 1, real only.
constant_power_2_real	double	W	IO	Constant power load on phase 2, real only.
constant_power_12_real	double	W	IO	Constant power load on phase 12, real only.
constant_power_1_reac	double	VAr	IO	Constant power load on phase 1, imaginary only.
constant_power_2_reac	double	VAr	IO	Constant power load on phase 2, imaginary only.
constant_power_12_reac	double	VAr	IO	Constant power load on phase 12, imaginary only.
constant_current_1	complex	A	IO	Constant current load on phase 1 (to neutral).
constant_current_2	complex	A	IO	Constant current load on phase 2 (to neutral).
constant_current_12	complex	A	IO	Constant current load on phase 12 (between phases, delta connection).
constant_current_1_real	double	A	IO	Constant current load on phase 1, real only.
constant_current_2_real	double	A	IO	Constant current load on phase 2, real only.
constant_current_12_real	double	A	IO	Constant current load on phase 12, real only.
constant_current_1_reac	double	A	IO	Constant current load on phase 1, imaginary only.
constant_current_2_reac	double	A	IO	Constant current load on phase 2, imaginary only.
constant_current_12_reac	double	A	IO	Constant current load on phase 12, imaginary only.
constant_impedance_1	complex	Ohm	IO	Constant impedance load on phase 1 (to neutral).
constant_impedance_2	complex	Ohm	IO	Constant impedance load on phase 2 (to neutral).
constant_impedance_12	complex	Ohm	IO	Constant impedance load on phase 12 (between phases, delta connection).
constant_impedance_1_real	double	Ohm	IO	Constant impedance load on phase 1, real only.
constant_impedance_2_real	double	Ohm	IO	Constant impedance load on phase 2, real only.
constant_impedance_12_real	double	Ohm	IO	Constant impedance load on phase 12, real only.
constant_impedance_1_reac	double	Ohm	IO	Constant impedance load on phase 1, imaginary only.
constant_impedance_2_reac	double	Ohm	IO	Constant impedance load on phase 2, imaginary only.
constant_impedance_12_reac	double	Ohm	IO	Constant impedance load on phase 12, imaginary only.

Measurement Properties

These properties are computed by the simulation and are output only. Note that the measured_voltage properties lag by one powerflow iteration; for the most current values, read the corresponding voltage_* properties from the parent triplex_node object directly.

Table 3: triplex_load table 3
Property Name	Type	Unit	I/O	Description
measured_voltage_1	complex	V	O	Measured voltage on phase 1.
measured_voltage_2	complex	V	O	Measured voltage on phase 2.
measured_voltage_12	complex	V	O	Measured voltage on phase 12 (between phases).
indiv_measured_power_1	complex	VA	O	Measured power on phase 1.
indiv_measured_power_2	complex	VA	O	Measured power on phase 2.
indiv_measured_power_12	complex	VA	O	Measured power on phase 12.
measured_power	complex	VA	O	Total measured power.

Base Power and ZIP Fraction Properties

These properties provide an alternative way to specify ZIP loads using a base power value with fraction and power factor breakdowns per phase, following the same conventions as the ZIPload object. When base_power is nonzero for a phase, it overrides the corresponding constant_power, constant_current, and constant_impedance values for that phase.

Table 4: triplex_load table 4
Property Name	Type	Unit	I/O	Description
base_power_1	double	VA	I	Nominal power on phase 1 before applying ZIP fractions.
base_power_2	double	VA	I	Nominal power on phase 2 before applying ZIP fractions.
base_power_12	double	VA	I	Nominal power on phase 12 before applying ZIP fractions.
power_pf_1	double	pu	I	Power factor of the phase 1 constant power portion of load.
current_pf_1	double	pu	I	Power factor of the phase 1 constant current portion of load.
impedance_pf_1	double	pu	I	Power factor of the phase 1 constant impedance portion of load.
power_pf_2	double	pu	I	Power factor of the phase 2 constant power portion of load.
current_pf_2	double	pu	I	Power factor of the phase 2 constant current portion of load.
impedance_pf_2	double	pu	I	Power factor of the phase 2 constant impedance portion of load.
power_pf_12	double	pu	I	Power factor of the phase 12 constant power portion of load.
current_pf_12	double	pu	I	Power factor of the phase 12 constant current portion of load.
impedance_pf_12	double	pu	I	Power factor of the phase 12 constant impedance portion of load.
power_fraction_1	double	pu	IO	Constant power fraction of base power on phase 1. May be overwritten if ZIP fractions do not sum to 1.
current_fraction_1	double	pu	I	Constant current fraction of base power on phase 1.
impedance_fraction_1	double	pu	I	Constant impedance fraction of base power on phase 1.
power_fraction_2	double	pu	IO	Constant power fraction of base power on phase 2. May be overwritten if ZIP fractions do not sum to 1.
current_fraction_2	double	pu	I	Constant current fraction of base power on phase 2.
impedance_fraction_2	double	pu	I	Constant impedance fraction of base power on phase 2.
power_fraction_12	double	pu	IO	Constant power fraction of base power on phase 12. May be overwritten if ZIP fractions do not sum to 1.
current_fraction_12	double	pu	I	Constant current fraction of base power on phase 12.
impedance_fraction_12	double	pu	I	Constant impedance fraction of base power on phase 12.

Triplex Load State of Development

Triplex_load is considered a well developed and validated model, with a number of features. Additional features may be included as needed.