Industrial and agricultural loads

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:

$$ \begin{bmatrix} Z_p \\ Z_q \\ I_m \\ I_a \\ P_p \\ P_q \end{bmatrix} = \begin{bmatrix} Zp_T & Zp_H & Zp_S & Zp_W & Zp_R & Zp \\ Zq_T & Zq_H & Zq_S & Zq_W & Zq_R & Zq \\ Im_T & Im_H & Im_S & Im_W & Im_R & Im \\ Ia_T & Ia_H & Ia_S & Ia_W & Ia_R & Ia \\ Pp_T & Pp_H & Pp_S & Pp_W & Pp_R & Pp \\ Pq_T & Pq_H & Pq_S & Pq_W & Pq_R & Pq \end{bmatrix} \ \begin{bmatrix} T_t \\ H_t \\ S_t \\ W_t \\ R_t \\ 1 \end{bmatrix} $$

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

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

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

where
 * is the minute of hour;
 * is the hour of day;
 * is the day of month;
 * is the month of year;
 * is the day of week;
 * 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.