Plug Load

The plugload object is an explicit residential end-use model for generic plug-connected devices. It inherits from residential_enduse and computes voltage-dependent power using ZIP-style fractions.

plugload is typically used to represent aggregate miscellaneous electric loads in a house when a more specific appliance model is not needed.

Model behavior

Initialization and defaults

  • heatgain_fraction defaults to 0.90.
  • power_factor defaults to 0.90.
  • voltage_factor initializes to 1.0.
  • demand (shape.load) is initialized randomly between 0 and 0.1 (uniform).
  • If ZIP fractions are not provided, defaults are set to:
  • power_fraction = 1.0
  • current_fraction = 0.0
  • impedance_fraction = 0.0

Runtime updates

  • The model updates voltage_factor from the attached circuit voltage.
  • If the parent circuit breaker is open, power/current/admittance contributions are forced to zero.
  • In manual-demand mode (shape.type == MT_UNKNOWN):
  • Negative demand is clamped to 0.
  • Base ZIP terms are formed from demand and ZIP fractions.
  • Reactive power is derived from power_factor when valid.
  • actual_power is computed as voltage-adjusted apparent power:
\[ actual\_power = power + (current + admittance \cdot voltage\_factor) \cdot voltage\_factor \]

Properties

Table 1: Plug Load Properties
Property Name Type Unit Description
circuit_split double - Split/balance indicator for circuit assignment (-1 to +1).
demand double unit Demand multiplier (shape.load) for aggregate plug load behavior.
installed_power double kW Installed plug-load capacity (shape.params.analog.power).
actual_power complex kVA Voltage-adjusted apparent power of the plugload object.

The following inherited residential_enduse properties are commonly used with plugload:

  • power_factor
  • power_fraction, current_fraction, impedance_fraction
  • heatgain_fraction
  • shape / schedule linkage

Example

object plugload {
  name house1_plugs;
  parent house1;
  installed_power 1.2 kW;
  demand PLUGS*1.0;
  power_factor 0.95;
  power_fraction 0.5;
  current_fraction 0.3;
  impedance_fraction 0.2;
}

This example models schedule-driven plug loads with custom ZIP fractions and power factor.