## Contents

Industrial and agricultural loads are implemented using a parametric load model, calculating the real and imaginary current, power, and resistance load components based on the time and existing weather data.

# Parametric Loads

Parametric loads can be defined using the **pqload** object, which is derived from **powerflow::load**. A **pqload** object has varying contributions to constant impedance, current, and power depending on prevailing time and weather conditions, such as sunlight, temperature, humidity, wind speed, and rainfall. Each load component (Z, I, P) is nominally computed based on the prevailing weather and adjusted based on the time.

The weather load is computed from a linear transformation as a function of weather as follows:

where

- [math]Z[/math], [math]I[/math], [math]P[/math] are the constant impedance, current and power components of the load, with [math]_p[/math] and [math]_q[/math] indicated the real and reactive parts and [math]m[/math] and [math]a[/math] are the magnitude and angle, respectively;
- [math]T[/math] is the outdoor temperature at the time [math]t[/math] in °F;
- [math]R[/math] is the relative humidity at the time [math]t[/math] in %;
- [math]S[/math] is the solar gains at the time [math]t[/math] in Btu/h;
- [math]W[/math] is the wind speed at the time [math]t[/math] in mph;
- [math]R[/math] is the rainfall at the time [math]t[/math] in inch/h;

## Properties

The **pqload** object publishes the following variables, in addition to those published by **powerflow::load**.

Property | Type | Unit | Default | Description |
---|---|---|---|---|

schedule | char1024 | - | * * * * *:1.0; | The load schedule (default is always 1.0) |

weather | object | - | NULL | The climate object to use for this load. If NULL, the temperature coefficients will be ignored. |

Zp_T | double | ohm/degF | 0 | Resistance response to temperature |

Zp_H | double | ohm/% | 0 | Resistance response to humidity |

Zp_S | double | ohm.h/Btu | 0 | Resistance response to solar gains |

Zp_W | double | ohm/mph | 0 | Resistance response to wind |

Zp_R | double | ohm.h/in | 0 | Resistance response to rainfall |

Zp | double | ohm | ∞ | Invariant resistance |

Zq_T | double | F/degF | 0 | Capacitance response to temperature |

Zq_H | double | F/% | 0 | Capacitance response to humidity |

Zq_S | double | F.h/Btu | 0 | Capacitance response to solar gains |

Zq_W | double | F/mph | 0 | Capacitance response to wind |

Zq_R | double | F.h/in | 0 | Capacitance response to rainfall |

Zq | double | F | 0 | Invariant capacitance |

Im_T | double | A/degF | 0 | Current magnitude response to temperature |

Im_H | double | A/% | 0 | Current magnitude response to humidity |

Im_S | double | A.h/Btu | 0 | Current magnitude response to solar gains |

Im_W | double | A/mph | 0 | Current magnitude response to wind |

Im_R | double | A.h/in | 0 | Current magnitude response to rainfall |

Im | double | A | 0 | Invariant current magnitude |

Ia_T | double | deg/degF | 0 | Current angle response to temperature |

Ia_H | double | deg/% | 0 | Current angle response to humidity |

Ia_S | double | deg.h/Btu | 0 | Current angle response to solar gains |

Ia_W | double | deg/mph | 0 | Current angle response to wind |

Ia_R | double | deg.h/in | 0 | Current angle response to rainfall |

Ia | double | deg | 0 | Invariant current angle |

Pp_T | double | W/degF | 0 | Real power response to temperature |

Pp_H | double | W/% | 0 | Real power response to humidity |

Pp_S | double | W.h/Btu | 0 | Real power response to solar gains |

Pp_W | double | W/mph | 0 | Real power response to wind |

Pp_R | double | W.h/in | 0 | Real power response to rainfall |

Pp | double | W | 0 | Invariant real power |

Pq_T | double | VAr/degF | 0 | Reactive power response to temperature |

Pq_H | double | VAr/% | 0 | Reactive power response to humidity |

Pq_S | double | VAr.h/Btu | 0 | Reactive power response to solar gains |

Pq_W | double | VAr/mph | 0 | Reactive power response to wind |

Pq_R | double | VAr.h/in | 0 | Reactive power response to rainfall |

Pq | double | VAr | 0 | Invariant Reactive power |

input_temp | double | degF | -- | Observed temperature. Read only. |

input_humid | double | % | -- | Observed humidity. Read only. |

input_solar | double | Btu/h | -- | Observed solar gains. Read only. |

input_wind | double | mph | -- | Observed wind speed. Read only. |

input_rain | double | in/h | -- | Observed rainfall. Read only. |

output_admit_p | double | Ohm | -- | Observed resistance. Read only. |

output_admit_q | double | Ohm | -- | Observed capacitance. Read only. |

output_current_m | double | A | -- | Observed current magnitude. Read only. |

output_current_a | double | degrees | -- | Observed current angle. Read only. |

output_power_p | double | W | -- | Observed real power. Read only. |

output_power_q | double | VAr | -- | Observed reactive power. Read only. |

output_admittence | complex | Ohm | -- | Observed impedance. Read only. |

output_current | complex | A | -- | Observed complex current. Read only. |

output_power | complex | W | -- | Observed complex power. Read only. |

The schedule is defined based the POSIX standard for crontab. The general syntax is

```
```

moh hod dom moy dow[ lpu][; ...]

```
```

where

`moh`

is the minute of hour;`hod`

is the hour of day;`dom`

is the day of month;`moy`

is the month of year;`dow`

is the day of week;`lpu`

is the load per unit (optional, 1.0 if omitted);

The block may be repeated as many times as needed to complete the schedule. Any unscheduled time interval is assumed to be 0.